Question #07bcc

1 Answer
Feb 17, 2017

Substitute #rcos(theta)" for "x and rsin(theta)" for "y#, then write r as a function of #theta#.

Explanation:

Substitute #rcos(theta)" for "x and rsin(theta)" for "y#:

#5rcos(theta) - 4rsin(theta) = -7#

Remove the common factor r:

#r(5cos(theta) - 4sin(theta)) = -7#

Divide both sides by #5cos(theta)-4sin(theta)#:

#r = (-7)/(5cos(theta) - 4sin(theta))#

Multiply numerator and denominator by -1:

#r = 7/(4sin(theta)-5cos(theta))#