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The Unit Circle is a circle that has a radius of 1 and a center at the origin.
If you look at the unit circle 90 degrees is at the point (0,1).
Cosine is equal to the x value of a point on the Unit Circle.
The line created to the point (0,1) on the unit circle when the degree is 90 is completely vertical, which in turn makes the x value 0 and thus, cosine of 90 = 0.
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Why does x equal 0 when finding the sin of 90 degrees?
On the unit circle sin(90) degrees is at Y = 1 and as that is on the Y axis X will equal = 0. Ask yourself. Where would 90 degrees be on a 360 degree circle? Straight up.
1 over cos y is equal to?
1/cos y = sec y
What is cos2x equal to?
You can look up "trigonometric identities" in Wikipedia.Cos(2x), among other things, is equal to (cos x)^2 - (sin x)^2 If you meant cos squared x, or (cos x)^2, that is equal to (1 + cos(2x))/2
What is the value of 1- cos x when x is small?
1 - cos x as x approaches 0. what is the cos of 0? It is 1. So as x approaches 0 cos x approaches 1. 1 - 1 = 0 So as it gets very small the solutions gets smaller.
Show that sin x equals cos x for some angle t between 0 and 90?
sin(x) = cos(x)sin(x)/cos(x) = tan(x) = 1x = arctan(1) = 45 degreessin(45)=cos(45) = Sqrt(2)/2 Answer: By observation. Since Sine = Opposite over hypotenuse and Cosine = Adjacent over hypotenuse. Any right angle triangle where the opposite and adjacent sides are the same length will have Sine equal to Cosine. This only happens with an isosceles triangle (two sides are equal in length). When one angle is 90o the other two are 45o.
Determine the measure of angle A if 0 degrees is smaller than or equal to A which is smaller than or equal to 90 degrees and cos125 degrees equals negative cos A?
cos(125) = cos(180 - 55) = cos(180)*cos(55) + sin(180)*sin(55) = -cos(55) since cos(180) = -1, and sin(180) = 0 So A = 55 degrees.
Sin30 cos90 sin 90 cos30?
To simplify the expression sin(30°) cos(90°) sin(90°) cos(30°), we first evaluate the trigonometric functions at the given angles. sin(30°) = 1/2, cos(90°) = 0, sin(90°) = 1, and cos(30°) = √3/2. Substituting these values into the expression, we get (1/2) * 0 * 1 * (√3/2) = 0. Therefore, the final result of sin(30°) cos(90°) sin(90°) cos(30°) is 0.
If y equals arc cos 0 then y is equal to 0 1 90 or 180?
arccos(0) = 90 + 360.n (n is an element of the integers) and 90 and 360 are in degrees. Therefore if the answer is in the subset 0<x<360 or something similar, Then the answer is 90.
How cos 90 is 0?
Cos 90=0 because cos@=base/hyp and at 90degree base becomes zero since zero divided by anything is zero. RPHK_Haider...
What is the value of cos -90?
cos90=0
When does Cosx equal 0?
Cos(x) equals zero at 90 degrees and 270 degrees. If x exceeds 360 degrees, cos(x) will equal zero at any increment of 90 + 180(n) degrees. In radians, this is equivalent to (pi/2) + pi(n) radians.
What is the value of cosx at -90?
at -90 degrees the value of cos(x) is 0.
Why is sine 30 the same as cosine of 60?
sin(30) = sin(90 - 60) = sin(90)*cos(60) - cos(90)*sin(60) = 1*cos(60) - 0*sin(60) = cos(60).
What are the 6 trig functions for 0 degrees 90 degrees 180 degrees 270 degrees?
sin(0) = 0, sin(90) = 1, sin(180) = 0, sin (270) = -1 cos(0) = 1, cos(90) = 0, cos(180) = -1, cos (270) = 0 tan(0) = 0, tan (180) = 0. cosec(90) = 1, cosec(270) = -1 sec(0) = 1, sec(180) = -1 cot(90)= 0, cot(270) = 0 The rest of them: tan(90), tan (270) cosec(0), cosec(180) sec(90), sec(270) cot(0), cot(180) are not defined since they entail division by zero.
What is cos squared 90 - theta?
The expression (\cos^2(90^\circ - \theta)) can be simplified using the co-function identity, which states that (\cos(90^\circ - \theta) = \sin(\theta)). Therefore, (\cos^2(90^\circ - \theta) = \sin^2(\theta)). This means that (\cos^2(90^\circ - \theta)) is equal to the square of the sine of (\theta).
Can two non-zero vector got a zero resultant?
Yes.If the angle between them is 90 degrees. As we know that A.B=|A| |B| cos (phi). When phi=90 degree,cos 90=0. Hence A.B= |A| |B| *0 =0.
Why is cos (x) sin (90-x) for x such that 0 x 90?
The identity (\cos(x) = \sin(90^\circ - x)) arises from the co-function relationship in trigonometry. For angles in the range (0^\circ \leq x \leq 90^\circ), the sine of an angle is equal to the cosine of its complementary angle. Thus, when you replace (90^\circ - x) with (x) in the sine function, you obtain (\cos(x)). This relationship highlights the symmetry of the sine and cosine functions in a right triangle.
