Answer 1:
Option C - Both procedures are correct.
Explanation:
As for Keisha's method of solving the question
- Tan^2 Q + 1 = Sec^2Q
- Sin^2 Q/ Cos^2 Q +1 = 1 / Cos^2 Q
- (8/17)^2 / Cos^2 Q + 1 / Cos ^2 Q
- Cos Q = +- Square root of 1 - 64/289
- Cos Q = +- 15/17
Therefore, Keisha's procedure is correct
Answer 2:
Option C - Both procedures are correct.
Explanation:
As for David's method of solving the question.
- Sin^2 Q + Cos^2 Q = 1
- Cos^2 Q = 1 - (-8/17)^2
- Cos Q = +- Square Root of 225/289
- Cos Q = +- 15/17
Therefore David's procedure is correct.