Multiple ChoiceFind the exact value of the expression.cos80°cos20°+sin80°sin20°\cos80\degree\cos20\degree+\sin80\degree\sin20\degreecos80°cos20°+sin80°sin20°54views
Multiple ChoiceExpand the expression using the sum & difference identities and simplify.sin(−θ−π2)\sin\left(-\theta-\frac{\pi}{2}\right)sin(−θ−2π)54views
Multiple ChoiceExpand the expression using the sum & difference identities and simplify.tan(−θ−π2)\tan\left(-\theta-\frac{\pi}{2}\right)tan(−θ−2π)47views
Multiple ChoiceFind cos(a+b)\cos\left(a+b\right)cos(a+b) given cosa=12\cos a=\frac12cosa=21, sinb=12\sin b=\frac12sinb=21, & aaa is in Q IV and bbb is in Q II.54views