What is the Cartesian form of $( -7 , (-3pi)/4 )$ ?

Question

1986 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-12-02T18:05:36

The cartesian equivalent is $((7sqrt(2))/2,(7sqrt(2))/2)$ .

In polar we have:
$x = r*cos(\theta)$
$y = r*sin(\theta)$

In the given ordered pair $r=-7$ and $theta=-(3pi)/4$ .

Substituting gives:
$x=-7cos(-(3pi)/4) = -7(-sqrt(2)/2)=(7sqrt(2))/2$
$y=-7sin(-(3pi)/4) = -7(-sqrt(2)/2)=(7sqrt(2))/2$

So the cartesian equivalent is $((7sqrt(2))/2,(7sqrt(2))/2)$ .

What is the Cartesian form of ( -7 , (-3pi)/4 ) ( -7 , (-3pi)/4 ) ?