Question

A= 4Cos²60- 4ctg45-3csc30

Answer 1

$cos60= 1/2 \\ ctg 45 = 1 \\ csc30=2 \\ a = 4( \frac{1}{2} )^{2} - 4(1) - 2 \\ a = 4( \frac{1}{4} ) - 4 - 2 \\ a = 1 - 4 - 2 \\ a = - 3 - 2 \\ a = - 5$