In here, you can calculate the value of its sides and angles within minutes. Question- What are Trigonometric identities?Īnswer- Trigonometric identities are quite beneficial for right angles triangles. Solution: Using the identity, sin 2θ + cos 2θ = 1 Q: For a right angle triangle ABC right angle at C for which angle BAC = θ and sinθ = 4/5 Find the value of cosθ.

Moreover, these identities are also useful for practical life situations, for example, calculation of heights of buildings that we have just calculated. Trigonometric identities are very useful for Right Angle triangles where you can calculate the value of its sides and angles in just minutes. Identities do not only rule the world of algebra but also have a colony in the province of Geometry as we have seen above.

This time divide the equation by (BC) 2 and substitute the values.

The above relation can also be derived in the same way by dividing the Pythagorean equation, Step 1: Divide the equation 1 by (AC) 2 we get, Step 3: Now, sin θ =Perpendicular/ Hypotenuse= (AC) /(AB)ġ= sin 2θ + cos 2θ Trigonometric Identity 2 (AB) 2= (AC) 2+ (BC) 2 let be equation (1)ĭividing equation 1 by square of AB on both the sides, Step 1: Consider a right angle triangle ABC, let angle C be of 90. (Hypotenuse) 2= (Base) 2 + (Perpendicular) 2 sin θ = 1/ cosec θ or sin θ x cosec θ = 1Īgain, as the name suggests, quotient relations involve three trigonometric ratios where one is the quotient obtained after division operation between the other two.Trigonometric Relations Reciprocal RelationshipĪs the name suggests, these relations involve two trigonometric ratios which are connected by inverse relations between them.

You can download Trigonometry Cheat Sheet by clicking on the download button belowīrowse more Topics under Introduction To Trigonometry Any trigonometric identity dealing with any variable of a right angle triangle will be satisfied by any value within an acceptable range of that variable. The equations can be seen as facts written in a mathematical form, that is true for “ right angle triangle”. The same applies to trigonometric identities also. For example (x+1) 2=x 2+2x+1 is an identity in x. In algebraic form, an identity in x is satisfied by some particular value of x.

Trig identity cheat sheet