AM-2667

R-formula

A Math · Secondary 4 · Hard · R-formula

The height

h

cm of a point on a rotating arm is given by

h = 3\cos\theta + 4\sin\theta

, where

\theta

is in radians. Express

h

in the form

R\sin(\theta + \alpha)

, where

R>0

and

\alpha

is an acute angle.

$h = 5\sin\bigl(\theta + \tan^{-1}(3/4)\bigr)$
$h = 5\sin\bigl(\theta + \tan^{-1}(4/3)\bigr)$
$h = 5\cos\bigl(\theta + \tan^{-1}(3/4)\bigr)$
$h = 5\sin\bigl(\theta - \tan^{-1}(3/4)\bigr)$

Sign in to check your answer and see the hint and the worked explanation. Free on PrepLab High.

Loading problem…