Exam 3 Math 136 PreCalculus Fall 2016 Dr Yunjiao Wang te Ple

Exam 3 (Math 136 PreCalculus, Fall 2016) Dr. Yunjiao Wang te: Please write down the necessary steps. Otherwise, zero credit will be assigned. 15 points) Suppose tan -1 and K 0 S T, find the exact values of sin e, cos e ec 6, csc 0 and cot

Solution

tan = -2/3            [ is in IInd quadrant]

Now

cot = 1/tan = -3/2

sec = sqrt[1 + tan^2 ] = sqrt[1 + 4/9] = -13/3

cos = 1/sec = -3/13

sin = sqrt[1 – cos^2 ] = sqrt[1 – 9/13] = 2/13

csc = 1/sin = 13/2