The displacement of a certain object is given as a function of the time (in seconds) by . Find the smallest positive value of for which the displacement is zero.
Is the answer
Yes. The third and fourth quadrant angles are and , the 'calculator answer') respectively.
Then and where n is an integer.
When workng with models involving trigonometric functions, the implied unit for the angle will always be radians. Note that the formulae for the derivative of sin x, cos x, tan x etc are for x measured in radians.