(A) (B) (C) (D) solution: Equation of the curve is ……….(i) Slope of the tangent to curve (i) at any point = Slope of the normal = negative reciprocal = [ Slopes of lines making equal...
Choose the correct answer in:The normal to the curve x ^2 = 4y passing (1,2) is (A) x + y = 3 (B) x – y = 3 (C) x + y = 1 (D) x – y = 1
Equation of the curve is ………..(i) Slope of the normal at = ……….(ii) Again slope of normal at given point (1, 2) = ……….(iii) From eq. (ii) and (iii), we have From eq. (i), ...
Choose the correct answer in: The normal at the point (1,1) on the curve 2y + x ^2 = 3 is (A) x + y = 0 (B) x – y = 0 (C) x + y +1 = 0 (D) x – y = 1
Equation of the given curve is ……….(i) Slope of the tangent to the given curve at point (1, 1) = (say) Slope of the normal = Equation of the normal at (1, 1) is Therefore, The...
Choose the correct answer in: A cylindrical tank of radius 10 m is being filled with wheat at the rate of 314 cubic metre per hour. Then the depth of the wheat is increasing at the rate of (A) 1 m/h (B) 0.1 m/h (C) 1.1 m/h (D) 0.5 m/h
Equation of the curve is ……….(i) Slope of the tangent to the given curve at point = ……….(ii) Now …..(iii) Putting the values of and in eq. (i), Therefore, The correct...
Choose the correct answer in The slope of the tangent to the curve x = t^ 2 + 3t – 8, y = 2t^ 2 – 2t – 5 at the point (2,– 1) is (A) 22/ 7 (B) 6 /7 (C) 7/ 6 (D) -6/ 7
Equation of the curves are …..(i) and …..(ii) and Slope of the tangent to the given curve at point = …..(iii) At the given point and At , from eq. (i), At , from eq. (ii), ...
Choose the correct answer in the questions :A cylindrical tank of radius 10 m is being filled with wheat at the rate of 314 cubic meter per hour. Then the depth of wheat is increasing at the rate of: (A) 1 m/h (B) 0.1 m/h (C) 1.1 m/h (D) 0.5 m/h
Let be the depth of the wheat in the cylindrical tank of radius 10 m at time V = Volume of wheat in cylindrical tank at time cu. m It is given that = 314 cu. m/hr 1 m/h Therefore,The...
Show that height of the cylinder of greatest volume which can be inscribed in a right circular cone of height h and semi vertical angle α is one-third that of the cone and the greatest volume of cylinder is 4 /27πh^3tan^2 α .
Let be the radius of the right circular cone of height Let the radius of the inscribed cylinder be and height In similar triangles APQ and ARC, Volume of cylinder (V) = ……….(ii) V = ...
Show that the height of the cylinder of maximum volume that can be inscribed in a sphere of radius R is 2R/√3 . Also find the maximum volume.
Let be the radius and be the height of the cylinder inscribed in a sphere having centre O and radius R. In right triangle OAM, AM2 + OM2 = OA2 ……….(i) Volume of cylinder (V) = ……….(ii) V...
Let f be a function defined on [a, b] such that f ′(x) > 0, for all x ∈ (a, b). Then prove that f is an increasing function on (a, b).
Let I be the interval Given: for all in an interval I. Let I with By Lagrange’s Mean Value Theorem, we have, where where Now ……….(i) Also, for all in an interval I From eq. (i), ...
Show that the altitude of the right circular cone of maximum volume that can be inscribed in a sphere of radius r is 4r/3
Let be the radius of base of cone and be the height of the cone inscribed in a sphere of radius OD = AD – AO = In right angled triangle OBD, OD2 + BD2 = OB2 ……….(i) Volume of cone (V)...
Find the absolute maximum and minimum values of the function f given by f (x) = cos^2 x + sin x, x ∈ [0, π]
……….(i) = = Now = 0 or or [Turning points] Now = 0 + 1 = 1 1 + 0 = 1 = 1 Therefore, absolute maximum is and absolute minimum is...
Find the points at which the function f given by f (x) = (x – 2)^4 (x + 1)^3 has (i) local maxima (ii) local minima (iii) point of inflexion.
Given: ……….(i) = = = Now = 0 or or or or Now, for values of close to and to the left of . Also for values of close to and to the right of . Therefore, is the point of local maxima....
A point on the hypotenuse of a triangle is at distance a and b from the sides of the triangle. Show that the minimum length of the hypotenuse is (a^2/3+b^2/3)^3/2
Let P be a point on the hypotenuse AC of a right triangle ABC such that PL AB = and PM BC = and let BAC = MPC = , then in right angled AP = PL = And in right angled PMC, PM = PM Let AC = then...
A window is in the form of a rectangle surmounted by a semicircular opening. The total perimeter of the window is 10 m. Find the dimensions of the window to admit maximum light through the whole opening.
Let m be the radius of the semi-circular opening of the window. Then one side of rectangle part of window is and m be the other side of rectangle. Perimeter of window = Semi-circular arc AB +...
The sum of the perimeter of a circle and square is k, where k is some constant. Prove that the sum of their areas is least when the side of square is double the radius of the circle
Let be the radius of the circle and be the side of square. According to question, Perimeter of circle + Perimeter of square = ……….(i) Let be the sum of areas of circle and square. [From...
A tank with rectangular base and rectangular sides, open at the top is to be constructed so that its depth is 2 m and volume is 8 m^3 . If building of tank costs Rs 70 per sq metres for the base and Rs 45 per square metre for sides. What is the cost of least expensive tank?
Given: Depth of tank = 2 m Let m be the length and m be the breadth of the base of the tank. Volume of tank = 8 cubic meters Cost of building the base of the tank at the rate of ` 70 per sq....
Find the maximum area of an isosceles triangle inscribed in the ellipse x^2/a^2+^2/b^2 with its vertex at one end of the major axis.
Equation of the ellipse is ……….(i) Comparing eq. (i) with we have and and Any point on ellipse is P Draw PM perpendicular to axis and produce it to meet the ellipse in the point Q. OM = and...
Find the intervals in which the function f given by f ( x)=x^3+1/x^3 , x≠0 is (i) increasing (ii) decreasing.
= = = ……….(i) Now = 0 = 0 Here, is positive for all real or [Turning points] Therefore, or divide the real line into three sub intervals and For , from eq. (i) at (say),...
Find the intervals in which the function f given by f(x)=4sinx-2x-xcosx/2+cosx is (i) increasing (ii) decreasing.
= = = = = = = ……….(i) Now for all real as . Also > 0 (i) is increasing if , i.e., from eq. (i), lies in I and IV quadrants, i.e., is increasing for and and (ii) is decreasing...
Show that the normal at any point θ to the curve x = a cosθ + a θ sin θ, y = a sinθ – aθ cosθ is at a constant distance from the origin.
The parametric equations of the curve are And Slope of tangent at point = Slope of normal at any point = And Equation of normal at any point i.e., at = is Distance of normal...
Find the equation of the normal to curve x^2 = 4y which passes through the point (1, 2).
Equation of the curve is ……….(i) Slope of the tangent to the curve at the point (1, 2) to curve (i) is =1 Slope of the normal to the curve at (1, 2) is Equation of the normal to the curve (i)...
The two equal sides of an isosceles triangle with fixed base b are decreasing at the rate of 3 cm per second. How fast is the area decreasing when the two equal sides are equal to the base ?
Let BC = be the fixed base and AB = AC = be the two equal sides of given isosceles triangle. Since cm/s ……….(i) Area of x BC x AM = = = [By chain rule] = cm2/s Now when cm2/s Therefore,...
Show that the function given by f(x)=log (x )/ x has maximum at x = e.
Here ……….(i) ……..(ii) And = ……….(iii) Now From eq. (iii), = = < 0 is a point of local maxima and maximum value of is...
Using differentials, find the approximate value of each of the following: (a) (17/81)^1/4 (b) 33^(-1/3)
Assume ……….(i) = ……….(ii) Changing to and to in eq. (i), we have ……….(iii) Here and From eq. (iii), 0.677 (b) Let ……….(i) = ……….(ii) Changing to and to in eq. (i), we have...