Given that tan (t) = 5 12, and 0 < t < π 2, complete the steps to find cos (t). Which identity would be best to start with?

1 tan2 (t) + 1=sec2 (t)

2 169/144

3 cos (t) = 1 / sec (t)

4 12/13

12/13

Step-by-step explanation:

Use a Pythagorean identity that has tangent.

tan² (t) + 1 = sec² (t)

(5/12) ² + 1 = sec² (t)

25/144 + 1 = sec² (t)

169/144 = sec² (t)

sec (t) = ±13/12

cos (t) = ±12/13

Since 0 < t 0.

cos (t) = 12/13