Michael J. answered • 11/04/15
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Effective High School STEM Tutor & CUNY Math Peer Leader
First, you need to know that cos(90) = 0. Knowing this, the term -2x2cos(90) gets eliminated from the equation.
8100 = x2 + 25600
Subtract 25600 on both sides of the equation.
-17500 = x2
Square-root both sides of the equation.
±√(-17500) = x
±√(-2500) √(7) = x
±√(2500)√(-1)√(7)= x
±50i√7 = x
-50i√7 = x and 50i√7 = x
The solutions are complex.
Michael J.
Since time is the subject, we isolate time on one side of the equation. Multiply time on both sides of the equation to get
(time)*(speed) = distance
Now divide both side of the equation by speed.
time = distance / speed
By the way, unit for speed should be km / time unit.
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11/04/15
Jack N.
In the first question, the answer was 50i square root seven. What is that in decimal form?
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11/04/15
Jack N.
11/04/15