Find the rectangular coordinates of (7, 9/4 π) ?!

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precalc hw

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Answer 1 · 2018-05-09T12:07:08

Rectangular coordinates are $\frac{7 \sqrt{2}}{2}, \frac{7 \sqrt{2}}{2}$ $(7 sqrt 2)/2, (7 sqrt 2)/2$

Polar coordinate is $r = 7, θ = \frac{9}{4} π = (2 π + \frac{π}{4}) = \frac{π}{4}$ $r= 7 , theta = 9/4 pi=(2 pi+pi/4) = pi/4$

Rectangular coordinates are $(r cos θ, r sin θ)$ $(r cos theta, r sin theta)$ or

$(7 cos (\frac{π}{4}), 7 sin (\frac{π}{4})) = \frac{7}{\sqrt{2}}, \frac{7}{\sqrt{2}}$ $(7 cos (pi/4), 7 sin (pi/4)) = 7/sqrt 2 , 7/sqrt 2$

$= \frac{7 \sqrt{2}}{2}, \frac{7 \sqrt{2}}{2}$ $= (7 sqrt 2)/2, (7 sqrt 2)/2$

Rectangular coordinates are $\frac{7 \sqrt{2}}{2}, \frac{7 \sqrt{2}}{2}$ $(7 sqrt 2)/2, (7 sqrt 2)/2$ [Ans]