Question 56

If (1 - cosA)/(1 + cosA) = x, then the value of x is

Solution

Expression : $$\frac{1 - cos A}{1 + cos A}$$

Multiplying both numerator and denominator by $$(1 - cos A)$$

= $$\frac{1 - cos A}{1 - cos A} \times \frac{(1 - cos A)}{(1 - cos A)}$$

= $$\frac{(1 - cos A)^2}{1 - cos^2 A} = \frac{(cos A - 1)^2}{sin^2 A}$$

= $$(\frac{cos A - 1}{sin A})^2 = (\frac{cos A}{sin A} - \frac{1}{sin A})^2$$

= $$(cot A - cosec A)^2$$

=> Ans - (B)

Share on Whatsapp Share on Whatsapp

Create a FREE account and get: