Find a polar equation for the curve represented by the given Cartesian equation. ?

x + y = 9

then

r cosθ + r sinθ = 9

r = 9/(cosθ + sinθ) .

x = r*cos(theta) y = r*sin(theta) subsequently you get: r^2*cos^2(theta) + r^2*sin^2(theta) = 36 element out the r^2 words: r^2(sin^2(theta) + cos^2(theta)) = 36 bear in mind trig identification: sin^2(x) + cos^2(x) = a million So: r^2 * (a million) = 36 subsequently we get: r=6 and r= (-6) those are actual an identical in polar coordinates. it relatively is graphed as a circle with a radius of 6 with the beginning because of the fact the middle of the circle. wish this facilitates.