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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.
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.
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
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.
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...
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.
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.
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.
Find all values of x that satisfy the condition cosx equals 0 where 0degrees is less than or equal to x is less than 360degrees?
cos x = 0; 0 ≤ x ≤ 360° x = 90° or x = 270° ( 90° + 180°)
What is tan of 90 degrees?
On the unit circle at 90 degrees the 90 degrees in radians is pi/2 and the coordinates for this are: (0,1). The tan function = sin/cos. In the coordinate system x is cos and y is sin. Therefore (0,1) ; cos=0, & sin=1 . Tan=sin/cos so tan of 90 degrees = 1/0. The answer of tan(90) = undefined. There can not be a 0 in the denominator, because you can't devide by something with no quantity. Something with no quantity is 0. Or, on a limits point of view, it would be infinity.
Does sine 40 equal sin 20?
NO!!! Sine40 = Cosine50 = 0.64278... Sin30 = Cos 60 = 0.5 Sin 0 = Cos 90 = 0 Sin 90 = Cos 0 = 1 From Latin the word 'Sine' means 'curve'. Cosine means 'Complimentary Sine' or Complimentary curve'. The 'awkward' decimal numbers are based on a the radius of a circle, that radius being the hypotenuse of a right- triangle based at the circles origin/centre.
