How do you multiply e^((13 pi )/ 12 ) * e^( pi/4 i ) e13π12eπ4i in trigonometric form?

1 Answer
Jul 17, 2018

color(purple)(e^((13 pi)/(12) i) * e^(( pi)/4 i) ~~ -0.5 - 0.866 ie13π12ieπ4i0.50.866i

Explanation:

e^((13 pi)/(12) i) * e^(( pi)/4 i)e13π12ieπ4i

e^(i theta) = cos theta +i sin thetaeiθ=cosθ+isinθ

(3 pi)/8 ~~ 3.4034 , ( pi)/4 ~~ 0.78543π83.4034,π40.7854

:. e^((13 pi)/(12) i) = (cos ((13 pi)/12)+ i sin ((13 pi)/12))

= - 0.9659 - 0.2588 i , III Quadrant

:. e^(( pi)/4 i) = (cos (pi/4)+ i sin (pi/4)

~~ 0.7071 + 0.7071 i

:. e^((13 pi)/(12) i) * e^(( pi)/4 i)

~~( - 0.9659 - 0.2588 i ) * ( 0.7071 + 0.7071 i)

~~ -0.683 + 0.183 -0 .683 i - 0.183 i

color(purple)(e^((13 pi)/(12) i) * e^(( pi)/4 i) ~~ -0.5 - 0.866 i