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Example Questions
Example Question #1 : How To Find Positive Sine
If , what is
? Round to the nearest hundredth.
Recall that the sine wave is symmetrical with respect to the origin. Therefore, for any value , the value for
is
. Therefore, if
is
, then for
, it will be
.
Example Question #1 : How To Find Positive Sine
In a right triangle, cos(A) = . What is sin(A)?
In a right triangle, for sides a and b, with c being the hypotenuse, . Thus if cos(A) is
, then c = 14, and the side adjacent to A is 11. Therefore, the side opposite of angle A is the square root of
, which is
Since sin is
, sin(A) is
.
Example Question #2985 : Act Math
What is the value of ?
As with all trigonometry problems, begin by considering how you could rearrange the question. They often have hidden easy ways out. So begin by noticing:
Now, you can treat like it is any standard denominator. Therefore:
Combine your fractions and get:
Now, from our trig identities, we know that , so we can say:
Now, for our triangle, the is
. Therefore,
Example Question #1 : How To Find Positive Sine
Solve for :
if
Recall that the standard triangle, in radians, looks like:
Since , you can tell that
.
Therefore, you can say that must equal
:
Solving for , you get:
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