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You must think of the unit circle.

negative theta is in either radians or degrees and represents a specific area on the unit circle. Remember the unit circle is also like a coordinate plane and cos is the x while sin is the y coordinate. Here is an example:

cos(-45): The cos of negative 45 degrees is pi/4 and cos(45) is also pi/4

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Q: Why does cos negative theta equals positive theta?
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How do you solve theta if cos squared theta equals 1 and 0 is less than or equal to theta which is less than 2pi?

cos2(theta) = 1 so cos(theta) = ±1 cos(theta) = -1 => theta = pi cos(theta) = 1 => theta = 0


Should we find cos theta if sec theta equals -10?

No.


Why does cos negative theta equal cos postitive theta?

The cosine is simply the x-coordinate of the unitary circle. It helps to draw the circle, and the sine and cosine (x and y coordinates), to visualize this. The y-coordinate is the same for a positive angle and for the corresponding negative angle.


How do you find tan-theta when sin-theta equals -0.5736 and cos-theta is greater than 0?

-0.5736


What is cos theta times cos theta?

Cos theta squared


How would you solve and show work for cos2 theta if cos squared theta equals 1 and theta is in the 4th quadrant?

cos2(theta) = 1 cos2(theta) + sin2(theta) = 1 so sin2(theta) = 0 cos(2*theta) = cos2(theta) - sin2(theta) = 1 - 0 = 1


Given tan Theta equals negative 15 divided by 8 and 90 degrees is less than or equal to theta which is less than or equals to 180 state 5 other trigonometric ratios and determine the measure of theta?

sin(theta) = 15/17, cosec(theta) = 17/15 cos(theta) = -8/17, sec(theta) = -17/8 cotan(theta) = -8/15 theta = 2.0608 radians.


Find all angles in the interval 0 360 satisfying the equation cos theta equals 0.7902?

cos(theta) = 0.7902 arcos(0.7902) = theta = 38 degrees you find complimentary angles


What is cos of a negative angle?

The cosine function is an even function which means that cos(-x) = cos(x). So, if cos of an angle is positive, then the cos of the negative of that angle is positive and if cos of an angle is negative, then the cos of the negative of that angle is negaitive.


How do you solve 4 cosine squared theta equals 1?

4*cos2(theta) = 1 cos2(theta) = 1/4 cos(theta) = sqrt(1/4) = ±1/2 Now cos(theta) = 1/2 => theta = 60 + 360k or theta = 300 + 360k while Now cos(theta) = -1/2 => theta = 120 + 360k or theta = 240 + 360k where k is an integer.


What is cos 360 minus theta?

- cos theta


Is it possible for sin theta cos theta and tan theta to all be negative for the same value of theta?

No, they cannot all be negative and retain the same value for theta, as is shown with the four quadrants and their trigonemtric properties. For example, in the first quadrant (0