Simplify ? cos2a−sin2bsin2a∙sin2b−ctg2a∙ctg2b
1 Answer
Apr 5, 2018
Explanation:
We want to simplify
cos2(a)−sin2(b)sin2(a)sin2(b)−cot2(a)cot2(b)
We will use the identity
sin2(x)+cos2(x)=1
Thus
cos2(a)−sin2(b)sin2(a)sin2(b)−cot2(a)cot2(b)
cos2(a)−sin2(b)sin2(a)sin2(b)−cos2(a)cos2(b)sin2(a)sin2(b)
cos2(a)−sin2(b)−cos2(a)cos2(b)sin2(a)sin2(b)
cos2(a)(1−cos2(b))−sin2(b)sin2(a)sin2(b)
cos2(a)sin2(b)−sin2(b)sin2(a)sin2(b)
−sin2(b)(1−cos2(a))sin2(a)sin2(b)
−sin2(b)sin2(a)sin2(a)sin2(b)
−1