Graph sinusoidal functions: phase shift

$h$h is a trigonometric function of the form $h(x)=a\cos(bx+c)+d$h, left parenthesis, x, right parenthesis, equals, a, cosine, left parenthesis, b, x, plus, c, right parenthesis, plus, d.

Below is the graph of $h(x)$h, left parenthesis, x, right parenthesis. The function has a maximum point at $(-2\pi,3)$left parenthesis, minus, 2, pi, comma, 3, right parenthesis and a minimum point at $\left(-\dfrac{\pi}{2},-4\right)$left parenthesis, minus, start fraction, pi, divided by, 2, end fraction, comma, minus, 4, right parenthesis.

$\qquad h(x)=$h, left parenthesis, x, right parenthesis, equals