Question

if cos 9 theta = sin theta and 9 theta <90 degree , then the value of tan theta is ?
A 1/√3. B √3. C 1. D 0 ​

Answer 1

Answer:

$\cos(9 \alpha ) = \sin( \alpha ) \\ \sin(90 - 9 \alpha ) = \sin( \alpha ) \\ 90 - 9 \alpha = \alpha \\10 \alpha = 90 \\ \alpha = 9$

Step-by-step explanation:

tanA= tan9