Question

If A is in Quadrant II and cos A= -3/4, find an exact value for sin 2A

Answer 1

Recall sin 2A=2sinAcosA. Make your triangle in 2nd quad with Cos A=-3/4 and find sin A

Answer 2

I ended up with a decimal..

Answer 3

Exact value means basically not using a calculator, keeping square root as a number.

Answer 4

so what did you get for it?

Answer 5

Just put up your work for the problem and we would tell you where you are going wrong.

Answer 6

2(radical 7/4)(-3/4)

Answer 7

The numbers are correct, just cancel, simplify, keeping sq rt 7

Answer 8

so -6 radical 7 over 16?