If $tan\theta + cot\theta$ = 5, then $tan^{2}\theta + cot^{2}\theta$ is
1). 23
2). 25
3). 26
4). 24
tan$\theta$+ cot$\theta$ = 5
On squaring both sides,
(tan$\theta$ + cot$\theta$)2 = 52
=> tan2$\theta$ + cot2$\theta$ + 2 tan$\theta$.cot$\theta$= 25
=> tan2$\theta$ + cot2$\theta$ = 25 – 2 = 23.
2. What is the value of [1 – sin (90 – 2A)] / [1 + sin (90 + 2A)]?
3. If $sin(\theta + 18^{0})$ = $cos 60^{0}$ $(0 < \theta < 90^{0})$, then the value of $cos5\theta$ is
7. The value of $(1 + sec 20^{0} + cot 70^{0}) (1 - cosec 20^{0} + tan 70^{0})$ is equal to
9. If α + β = 90° and α:β = 2:1, then the ratio of cosα to cosβ is