Question

Question #5fe15

Answer 1

`sinx = 4/5`

Explanation:

Use `sin^2theta + cos^2theta = 1`.

`sin^2x + cos^2x = 1`

`sin^2x + (3/5)^2 = 1`

`sin^2x = 1 - 9/25`

`sin^2x = 16/25`

`sinx = +- 4/5`

But since the angle is described as being "positive acute", it must be in the firs quadrant, and so the ratio is positive.

Practice Exercises

`1`. Knowing that `tantheta = sintheta/costheta` and `sectheta = 1/costheta`, find the value of `tantheta` if `sectheta = 13/12` and `sintheta > 0`.

Solution

`1`. `tantheta = 5/12`

Hopefully this helps, and good luck!