To divide complex numbers in polar form, divide the r parts and subtract the angle parts. Or
<span><span><span><span>r2</span><span>(<span>cos<span>θ2 </span>+ i</span> sin<span>θ2</span>) / </span></span><span><span>r1</span><span>(<span>cos<span>θ1 </span>+ i</span> sin<span>θ1</span>)</span></span></span></span> <span>= <span><span><span>r2/</span><span>r1</span></span></span><span>(cos(<span><span>θ2</span>−<span>θ1) </span></span>+ i sin(<span><span>θ2</span>−θ1)</span><span>)
</span></span></span>
z1/z2
= 3/7 (cos(π/8-π/9) + i sin(π/8 - π/9))
= 3/7 (cos(π/72) + i sin(π/72))
Draw a line from F to (0,0). If you rotate that line 90 degree counterclockwise about the origin, the coordinate of F’ will be (4,1)
∑ ( from n = 1 to n =5 ) 3 · ( -2 ) ^( n -1 )
a 1 = 3 · ( -2 ) ^0 = 3
a 2 = 3 · ( - 2 ) = - 6
a 3 = 3 · 4 = 12
a 4 = 3 · ( - 8 ) = - 24
a 5 = 3 · 16 = 48
3 - 6 + 12 - 24 + 48 = 33
Answer: C ) 33
Answer:
approximation is often useful when it is not a very good one
If the 26 bricks are each 7 cm, seems like multiplication or repeated addition would solve the problem. Multiplication would be faster. 26 x 7 = 182
182 cm tall.
