Find the measures of two angles, one positive and one negative, that are coterminal with $\dfrac{\pi}{2}$.

$\dfrac{3\pi}{2} -\dfrac{\pi}{2}$

$\dfrac{\pi}{2}+360 -\dfrac{\pi}{2}-360$

$\dfrac{5\pi}{2} -\dfrac{\pi}{2}$

$\dfrac{5\pi}{2} -\dfrac{3\pi}{2}$ $\leftarrow$

Question

Find the measures of two angles, one positive and one negative, that are coterminal with $\dfrac{\pi}{2}$.

$\dfrac{3\pi}{2} -\dfrac{\pi}{2}$

$\dfrac{\pi}{2}+360 -\dfrac{\pi}{2}-360$

$\dfrac{5\pi}{2} -\dfrac{\pi}{2}$

$\dfrac{5\pi}{2} -\dfrac{3\pi}{2}$ $\leftarrow$

sleepyjess · Answer

@jim_thompson5910 @ganeshie8 @Hero

jim_thompson5910 · Answer

the only answer that looks correct is B, but the problem with choice B is that you should add on 2pi and NOT 360

the other answer choices are not coterminal to pi/2

jim_thompson5910 · Answer

choice D is incorrect because 5pi/2 - 3pi/2 = 2pi/2 = pi which is not equal to pi/2

sleepyjess · Answer

Why not choice A?

jim_thompson5910 · Answer

because

3pi/2 - pi/2 = 2pi/2 = pi

it's not equal to pi/2

sleepyjess · Answer

the answer choices must have typed out wrong, it should have been 2 answers in each choice

jim_thompson5910 · Answer

hmm, so you'll have to bring that typo up with the teacher