given cos A = 5 over radical 61 and that angle A is in Quadrant IV, find the exact value of tan A in simplest radical form, using a rational denominator

Question

The answer must be in simplest radical form with a rational denominator

 

Answer 1

5² + b² = (√61)²

25 + b² = 61

b² = 36

b = 6

 

tan A = -6/5