1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
galina1969 [7]
3 years ago
15

NEED HELP HERE PLEASE

Mathematics
1 answer:
loris [4]3 years ago
6 0
1. The answer is C. cos180=-1, sin180=0. 2*(cos180+i*sin180)=2*(-1+0)=-2. Check every other answer, none of which gets -2. 

2. The answer is C. cos270=0, sin270=-1. (You can draw out these angles to see). 2*(cos270+i*sin270)=2*(0-i)=-2i, as desired. Other choices don't work.

3. Answer A. Modulus of z is \sqrt(6^2+(-6)^2)=6*\sqrt(2). <span>The </span>angle<span> of the </span>point<span> on the complex </span>plane<span> is the </span>inverse tangent<span> of the complex portion over the real portion. Theta=arctan(-6/6), and arctan(-1)=-pi/4, so theta=-pi/4=-pi/4+2pi=7pi/4. So A is the correct answer.

4. The answer is A. As above, cos270=0, sin270=-1. 3(cos270+sin270*i)=3*(0-i)=-3i. This problem is similar to question 2.

5. </span>z1 = 7(cos 40° + i sin 40°), and z2 = 6(cos 145° + i sin 145°). z1*z2=7*6*(cos 40° + i sin 40°)*(cos 145° + i sin 145°)=42*(cos40*cos145-sin40*sin145+i*sin40*cos145+i*sin145*cos40). Use formula for sum/difference formula of cosines, cos40*cos145-sin40*sin145=cos(40+145)=cos185. Again, sin40*cos145+sin145*cos40=sin(40+145)=sin185. The answer is <span>42(cos 185° + i sin 185°).</span>
You might be interested in
PLEASE ANSWER LAST OF MY POINTS, DUE IN 10 MINUTES
makkiz [27]
No HAHAHAHAHAahhahahsiaijxjs
6 0
3 years ago
Answer question 14 please
Fittoniya [83]

Answer:

D

Step-by-step explanation:

Z is the only relation that does not pass the vertical line test, so Z is not a function.

Answer: D

7 0
1 year ago
Pre college need help
Goshia [24]

Answer:

f(-8) = 169

Step-by-step explanation:

3 0
2 years ago
Read 2 more answers
Simplify the polynomial. Then find its value for the given value of the variable.
zloy xaker [14]

Answer:

  • simplified: xy²
  • value: 4

Step-by-step explanation:

The polynomial is simplified by combining like terms. Like terms are identified more easily if the variables in each term are written in the same order. We usually like to use alphabetical order. Two of the like terms have opposite coefficients, so they cancel. The result is ...

  (3 1/2 -2 1/2)xy² +(-2 4/5 +2 4/5)x²y

  = xy² . . . . simplified expression

__

For x = 1, y = -2, the value of the expression is ...

  (1)(-2)² = 4

4 0
2 years ago
Which of the following statements is true.
mina [271]

Answer:

1st Statement is true i.e The higher your interest rate, the higher your monthly mortgage payments.

5 0
2 years ago
Other questions:
  • What is 25% of 15<br> Please help thank you!
    15·2 answers
  • What is the equation of the line that passes through (3,4) and is perpendicular to y=-2x-4
    5·1 answer
  • 10 points help fast please
    6·1 answer
  • PLEASE HELP!!!!!!!!!!!!!!
    13·1 answer
  • A linear equation that passes through (-6,-5) and parallel to 2x-3y=12
    7·1 answer
  • Please help ASAP and help me find what the value of x is
    14·2 answers
  • What is the solution of x-1/1-x &lt; 0?
    15·1 answer
  • Help please I need this as soon as posible ​
    12·2 answers
  • The object above is symmetrical through Y = 17 inches Z = 18 inches, and H = 11 inches, what is the area of the object ?
    6·1 answer
  • Find the zeros of the following<br> please solve step by step<br> 1. x³+9x²+26x+24=0
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!