The trigonometric attributes relate the angles of a triangle come the size of its sides. Trigonometric features are important in the research of routine phenomena like sound and light waves and also many other applications. The most acquainted three trigonometric ratios room sine function, cosine role and tangent function. Because that angles much less than a appropriate angle, trigonometric functions are commonly identified as the proportion of two sides the a right triangle containing the angle and also their values can be found in the size of various line segments around a unit circle.

You are watching: Sin -90 degrees

Sin 90 degrees = 1

The angles space calculated through respect come sin, cos and also tan functions which space the main functions, conversely, cosecant, secant and cot features are obtained from the primary functions. Usually, the levels are considered as 0°, 30°, 45°, 60°, 90°, 180°, 270° and 360°. Here, you will find out the worth for sin 90 degrees and how the values space derived together with other degrees or radian values.

Sine 90 degrees value

To specify the sine function of one acute angle, start with the right-angled triangle ABC through the edge of interest and the sides of a triangle. The 3 sides the the triangle are given as follows:


The opposite next – side opposite come the angle of interest.The hypotenuse next – opposite side of the best angle and it is always the longest next of a ideal triangleThe nearby side – remaining side that a triangle and it creates a next of both the angle of interest and the best angle

The sine function of an edge is equal to the size of the contrary side split by the size of the hypotenuse side and also the formula is provided by

\(\sin \theta =\fracopposite sidehypotenuse side\)

The sine regulation states that the political parties of a triangle are proportional to the sine of opposing angles.

\(\fraca\sin A=\fracb\sin B=\fracc\sin C\)

In the complying with cases, the sine preeminence is used. Those problems are

Case 1: provided two angles and one next (AAS and ASA)

Case 2: provided two sides and non contained angle (SSA)

Derivation to discover the worth of Sin 90 Degrees

Let us now calculate the worth of sin 90°. Think about the unit circle. The is the circle v radius 1 unit and also its centre inserted in origin.


From the basic knowledge the trigonometry, us conclude that for the given right-angled triangle, the base measuring ‘x’ units and also the perpendicular measure ‘y’ units.

We understand that,

For any right-angled triangle measure up with any kind of of the angles, sine attributes equal come the proportion of the length of the opposite next to the length of the hypotenuse side. So, from the figure

\(\sin \theta\) = y/1

Start measuring the angle from the an initial quadrant and end up through 90° when it reaches the positive y-axis. Now the worth of y becomes 1 because it touch the circumference of the circle. Thus the worth of y i do not care 1.

\(\sin \theta\) = y/1 = 1/1

Therefore, sin 90 level equals come the fractional value of 1/ 1.

Sin 90° = 1

The most common trigonometric sine attributes are

Sin 90 degree plus theta\(\sin (90^\circ+\theta )=\cos \theta\)Sin 90 degree minus theta\(\sin (90^\circ-\theta )=\cos \theta\)

Some various other trigonometric sine identities room as follows:

\(\sin x=\frac1\csc x\)\(\sin^2x+\cos ^2x=1\)\(\sin (-x)=-\sin x\)Sin 2x = 2 sin x cos x

In the same way, we have the right to derive various other values the sin angles like 0°, 30°,45°,60°,90°,180°,270° and 360°. Listed below is the trigonometry table, which defines all the worths of sine together with other trigonometric ratios.

Trigonometry proportion Table
Angles (In Degrees)030456090180270360
Angles (In Radians)0π/6π/4π/3π/2π3π/2
tan01/√31√3Not Defined0Not Defined0
cotNot Defined√311/√30Not Defined0Not Defined
cosecNot Defined2√22/√31Not Defined−1Not Defined
sec12/√3√22Not Defined−1Not Defined1

Cos 0 Degrees

The worth of cos 0 levels is same to the worth of sin 90 degrees.

Sin 90° = Cos 0° = 1

Solved Examples

Question 1: find the worth of sin 135°.


Given, sin 135° = sin ( 90° + 45° )

= cos 45° = 1 /√2

Therefore, the value of sin 135° is 1 /√2

Question 2: uncover the worth of cos 30°.


Given , cos 30° = cos ( 90° – 60° )

= Sin 60° = \(\frac\sqrt32\)Therefore, the value of cos 30° is \(\frac\sqrt32\).

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Practice Questions

evaluate the value of sin 90° + Cos 90°. Discover the value of 2sin 90° – sec 90° What is the value of (sin 90°)/2 – sin 30°?

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