Answer:
D.
Explanation:
The choices to this question are
a.) 1/tan(90-A)
b.) 1/sin A
c.) 1/cos(90-A)
d.) 1/tan A
We know that
, which is a trigonometric identity.
If
then,
![tan(90-A)=(sin(90-A))/(cos(90-A))](https://img.qammunity.org/2021/formulas/mathematics/middle-school/r2qwjlcevwx8k151i0athr3fkqfvlgb4h8.png)
But,
and
![cos(90-A)=sinA](https://img.qammunity.org/2021/formulas/mathematics/middle-school/ci48j6rv8rh2j7heoak8lw34v50w1annds.png)
So,
![tan(90-A)=(cosA)/(sinA)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/b0rxzmex1gvagr4v4uh54hs4kdiczyjcsk.png)
Which is the inverse of tangent, so
![tan(90-A)=(1)/(tanA)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/pw00bnemjknxu9iuc0mwvypf9e3k21ejl2.png)
Therefore, the right answer is D.