Answer:
(b) 7.28 cis(105.945°)
Step-by-step explanation:
The trig form of a vector is always ...
magnitude(cos(angle)·i +sin(angle)·j)
Sometimes, that is abbreviated ...
magnitude cis(angle) or magnitude∠angle
where the "angle" is measured counterclockwise from the +x axis.
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The forms showin in choices C and D can be rejected immediately because the sine and cosine coefficients are incorrectly placed. To differentiate between choices A and B, you need to know whether the angle is greater than 90°. The terminal point is above and left of the initial point, so the angle must be <em>more than 90°</em>. (It can help to plot the points on a graph.)
u = 7.28(cos 105.945°i + sin 105.945°j)
We can solve this by setting up 2 equations. We can use any letters like. For now, I'll use x and y.
So now we know that x - y = 0.7 and x + y = 1.
Now we can eliminate one of the letters by adding or subtracting one equation from the other. I am going to eliminate y by adding the two together (the y and the -y cancel).
This gives us 2x = 1.7, and so x = 1.7 ÷ 2 = 0.85
Finally, we can substitute x for 0.85 back into one of the original equations to figure out what y equals. I'm going to use x + y = 1.
So now we have 0.85 + y = 1, so y = 1 - 0.85 = 0.15
The numbers, therefore, are 0.85 and 0.15 (you can check by using the other equation).
Hope this helps!
Answer:
21 Black tokens are in the bag
Step-by-step explanation:
The answer is 2
-3.8+(-0.6)= -4.4
-4.4+6.4=2
Answer:
give me the choices for this question
