Answer:
3 sin(41t) - 3 sin(t)
Step-by-step explanation:
The general formula to convert the product of the form cos(a)sin(b) into sum is:
cos(a) sin(b) = 0.5 [ sin(a+b) - sin (a-b) ]
The given product is:
6 cos(21t) sin(20t) = 6 [ cos(21t) sin(20t) ]
Comparing the given product with general product mentioned above, we get:
a = 21t and b = 20t
Using these values in the formula we get:
6 cos(21t) sin(20t) = 6 x 0.5 [ sin(21t+20t) - sin(21t-20t)]
= 3 [sin(41t) - sin(t)]
= 3 sin(41t) - 3 sin(t)
Therefore, second option gives the correct answer
First thing to do is to change the radians to degrees so it's easier to determine our angle and where it lies in the coordinate plane.
. If we sweep out a 210 degree angle, we end up in the third quadrant, with a 30 degree angle. In this quadrant, x and y are both negative, but the hypotenuse, no matter where it is, will never ever be negative. So the side across from the 30 degree reference angle is -1, and the hypotenuse is 2, so the sine of this angle, opposite over hypotenuse, is -1/2
-2x^2 + 3x - 9 = 0
The quadratic is not factorable so quadratic formula must be used.
x = (-b + - √(b^2 - 4ac))/2a
a = -2, b = 3, c = -9
x = (-3 + - √(9 - 4*-2*-9))/-4
x = (-3 + - √(-63))/-4
x = -3 + - 3i√7
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-4
x = 3 + 3i√7 x = 3 - 3i√7
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4 4
