Question

Test for symmetry and graph the polar equation r=9cos (20) a. Is the polar equation symmetrical with respect to the polar axis? O A. No O A No OB. May or may not be symmetrical with respect to the polar axis OC. Yes b. Is the polar equation symmetrical with respect to the line ? મ O A. May or may not be symmetrical with respect to the line = OB. No OC. Yes c. Is the polar equation symmetrical with respect to the pole? O A. Yes O B. No OC. May or may not be symmetrical with respect to the pole d. Which graph represents the equation? ОА , Click to select your answer.

Answer 1

(①) Symmetric with pole- Sol" symmetric with pole - means Symmetric with eseigin. So, replacecrios o Ся-те) h = 9 Cos 20 -2=9 Cos 20 e= -9 Coszo Not symmetric with pole.

aus Solh l= q los2o To check that given polar equation is symmetric with polar axis an not So, polar -axis Cx-cruis) we replace (ro) with (4-0) or (-2, T-O) Soi d=q los 20 0 l I 9 Cos (-20) r = q Cos 207 Hence, this polar equation is symmetric with polar cris. (b) symmetric with line 0=an soln Symmetric with line means (Symmetric with y -axis) so, replace (r, O) with frite h = q los 2o -2= q cos(-20) -= 9 Cos 20 2= -9 Cos 20 Not symmetric with line osa (d) (B), graph is correct