The relationship between rectangular and rotational coordinates can be represented by the vector equation: r = x i + yj= r cos(theta)i + r sin(theta)j
What value(s) of θ make(s) |y| maximum?
So the options are 0. pi/3, pi/2, pi, 5pi/4, 3pi/4, pi/4, and 3pi/2.
I tried plugging in numbers to obtain y values and I got 3pi/2 to be the highest, then 5pi/4 then pi. It could be any or all of these answers. Any insight on how to tackle this problem is appreciated! thanks.

Question

The relationship between rectangular and rotational coordinates can be represented by the vector equation: r = x i + yj= r cos(theta)i + r sin(theta)j
What value(s) of θ make(s) |y| maximum?
So the options are 0. pi/3, pi/2, pi, 5pi/4, 3pi/4, pi/4, and 3pi/2. 
I tried plugging in numbers to obtain y values and I got 3pi/2 to be the highest, then 5pi/4 then pi. It could be any or all of these answers. Any insight on how to tackle this problem is appreciated! thanks.

shamim · Answer

I think u know that
y=r*sin (theta)

shamim · Answer

U know
Sin(pi/2)=1

shamim · Answer

So
y=r
And its maximum value of y

shamim · Answer

Because 1 is maximum value of sin (theta)

shamim · Answer

Can u try it for 3*pi/2

anonymous · Answer

yeah i put just 3pi/2 and it wasnt correct. so im stuck

shamim · Answer

Can u show ur work plz !