Considering Cosine rule, b² + c² - a²⁄2bc is equal to
A). cos A
B). cos B
C). cos C
D). cos D
1. If $sec (3x - 20^{0})$ = $cosec (3y + 20^{0})$, then what is the value of tan (x + y)?
3. The minimum value of $2sin^{2}\theta + 3cos^{2}\theta$ is
4. If $cos\theta $ = $\frac{p}{\sqrt{p^{2} + q^{2}}}$ ,then the value of $tan\theta $ is :
5. If $\frac{cosA}{(1 - sinA)} = x$, then the value of x is
6. If (cosA + sinA) /(cosA - sinA) = 7/6, then the value of (cot2A – 1) /(cot2A + 1) is?