If sin θ = 21/29, use the pythagorean identity to find cos θ. a. cos θ = ± 8 over 29 b. cos θ = ± 21 over 20 c. cos θ = ± 29 over 20 d. cos θ = ± 20 over 29

If If sin Θ = 21/29, then the y-component should be equal to 21 and the hypotenuse is equal to 29. In this case, using the pythgorean theorem, the x-component is obtained from (29^2-21^2)^1/2 equal to 20. Hence cos Θ should be +/-20/29. This has +/- because positive sine  can be  in quadrant II where cosine value is negative

In this problem it decreased 20%