The average term of this sequence is (1 +40)/2 = 20.5. The sum of the terms of this sequence is the number of terms (40) multiplied by the average term (20.5). That product is ...
40·20.5 = 820
Chu-Li will have added $820 to her bank in 40 weeks, so the total there is ...
$100 +820 = $920 . . . amount Chu-Li will have 40 weeks from now
the cube roots of 27(cos 330° + i sin 330°) will be </span>∛[27(cos 330° + i sin 330°)]
we know that e<span>^(ix)=cos x + isinx therefore </span>∛[27(cos 330° + i sin 330°)]------> ∛[27(e^(i330°))]-----> 3∛[(e^(i110°)³)] 3∛[(e^(i110°)³)]--------> 3e^(i110°)-------------> 3[cos 110° + i sin 110°]
z1=3[cos 110° + i sin 110°]
cube root in complex number, divide angle by 3 360nº/3 = 120nº --> add 120º for z2 angle, again for z3 <span>therefore </span> z2=3[cos ((110°+120°) + i sin (110°+120°)]------ > 3[cos 230° + i sin 230°]
z3=3[cos (230°+120°) + i sin (230°+120°)]--------> 3[cos 350° + i sin 350°] <span> the answer is
