We can find out the sine (or cosine or tangent) of either of the known- 90° angles. Question 2: What are the 3 trigonometric ratios?Īnswer: The 3 trigonometric ratios are sine, cosine and tangent. Then, for ∠BAC=θ, calculate the value of sinθ, cosθ and tanθ. If the hypotenuse=AB = 5cm, perpendicular=BC =4cm and base=AC= 3cm. Question 1: Consider a right angle triangle ABC right angled at C. Consider one famous mnemonic Some People Have, Curly Black Hair Through Proper Brushing. For example, representing the sine, cosine, and tangent (and their corresponding sides) as strings of letters can help us remember them. Source: Trigonometric Ratios MnemonicsĪ common use of mnemonics is to remember facts and relationships in trigonometry. What are the Properties of Inverse Trigonometric Functions? Trigonometric Ratios Table cotangent or cotθ= Base/Perpendicular= Adjacent/Opposite.secant or secθ = Hypotenuse/Base =Hypotenuse/ Adjacent.cosecant or cosecθ= Hypotenuse/Perpendicular= Hypotenuse/Opposite.
Also, it’s obvious that they are trigonometric ratios. The reciprocal of sin, cos, and tan can also have names. tangent or tanθ= Perpendicular/Base= Opposite/Adjacent.cosine or cosθ= Base/ Hypotenuse= Adjacent/Hypotenuse.sine or sinθ= Perpendicular/ Hypotenuse= Opposite/Hypotenuse.Hypotenuse: It is the side opposite to the right angle of the triangle (or the largest side).Opposite: It is the side opposite to angle being considered.Adjacent: It is the side adjacent to the angle being considered.But for ∠ABC, sinθ 2= Perpendicular/ Hypotenuse = AC/ABĬonfusing, isn’t? To remove this confusion, we will name different sides of the right-angled triangle as adjacent, opposite and hypotenuse.For ∠BAC, sinθ 1= Perpendicular/ Hypotenuse = BC/AB.(Right Angle Triangle ABC) Concepts of Trigonometric Ratiosįixing the base and perpendicular can be difficult sometimes. Then, for ∠BAC, value of sinθ = Perpendicular/ hypotenuse = BC/AB Also, if we chose AC as the base and BC as the perpendicular. In that case, side AB will be the hypotenuse. The most common trigonometric ratios are sine, cosine, and tangent.Ĭonsider a right-angle triangle ABC, right-angled at C. Trigonometric ratios are the ratios of sides of a right-angle triangle.
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