Question

3arccos (2x+3)=5pi/2

Answer 1

$3arccos(2x+3)=frac{5pi }{2}; ; to ; ; arccos(2x+3)=frac{5pi }{6}\\cos(arccos(2x+3))=cosfrac{5pi }{6}\\2x+3=cos(pi -frac{pi}{6})\\2x+3=-cosfrac{pi }{6}\\2x+3=-frac{sqrt3}{2}\\2x=-3-frac{sqrt3}{2}=-frac{6+sqrt3}{2}\\x=-frac{6+sqrt3}{4}$