Question

9: Find sinθ if cosθ=4/5 is in the first quadrant.

Answer 1

Answer: We have to find the sin(theta) provided the cos(theta) function, the visualization of the problem is as follows:

$cos(\theta)=\frac{4}{5}$

The diagram visualization is:

Therefore the x is:

$x=\sqrt{5^2-4^2}=3$

Therefore the answer is:

$sin(\theta)=\frac{3}{5}$

The answer is Option(C).