RD Sharma

43.\frac{(\cos ecA)}{(\cos ecA-1)}+\frac{(\cos ecA)}{(\cos ecA+1)}=2{{\sec }^{2}}A

Assuming the L.H.S and taking L.C.M and on simplifying we will get, $=\frac{(\cos ecA)(\cos ecA+1+\cos ecA-1)}{(\cos e{{c}^{2}}A-1)}$ $=\frac{(2\cos e{{c}^{2}}A)}{{{\cot }^{2}}A}$ $=\frac{2{{\sin...

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