Here you will learn what is the formula of cos 3A with proof and examples based on it. Letโs begin โ Cos 3A Formula The formula of cos 3A is \(4 cos^3 A โ 3 cos A\). Proof : We have, cos (A + B) = cos A cos B โ sin A sin B โฆ
Solution : We have, L.H.S = cos A cos (60 โ A) cos (60 + A) \(\implies\) L.H.S = cos A (\(cos^2 60 โ sin^2 A\)) [ By using this formula, cos (A + B) cos (A โ B) = \(cos^2 A\) โ \(sin^2 B\)ย above ] \(\implies\) L.H.S = cos A (\(1\over 4\) โ โฆ
Prove that cos A cos (60 โ A) cos (60 + A) = \(1\over 4\) cos 3A. Read More ยป
Solution : We have, L.H.S = sin A sin (60 โ A) sin (60 + A) \(\implies\) L.H.S = sin A (\(sin^2 60 โ sin^2 A\)) [ By using this formula, sin (A + B) sin (A โ B) = \(sin^2 A\) โ \(sin^2 B\)ย above ] \(\implies\) L.H.S = sin A (\(3\over 4\) โ โฆ
Prove that sin A sin (60 โ A) sin (60 + A) = \(1\over 4\) sin 3A. Read More ยป
Here you will learn what is the formula of sin 3A with proof and examples based on it. Letโs begin โ Sin 3A Formula The formula of sin 3A is \(3 sin A โ 4 sin^3 A\). Proof : We have, sin (A + B) = sin A cos B + cos A sin B โฆ
Solution : The value of tan 120 degrees is \(-\sqrt{3}\). Proof : We Know that tan 60 = \(\sqrt{3}\). By using formula of tan 2A, tan 120 = \(2 tan 60\over 1 โ tan^2 60\) = \(2 \times \sqrt{3}\over 1 โ 3\) \(\implies\)ย tan 120 = \(-\sqrt{3}\)
Solution : The value of cos 120 degrees is \(-1\over 2\). Proof : We Know that sin 60 = \(\sqrt{3}\over 2\) and cos 60 = \(1\over 2\) By using cos 2A formula, cos 120 = \(cos^2 60\) โ \(sin^2 60\) = \(1\over 4\) โ \(3\over 4\) \(\implies\)ย cos 120 = \(-1\over 2\)
Solution : The value of sin 120 degrees is \(\sqrt{3}\over 2\). Proof : We Know that sin 60 = \(\sqrt{3}\over 2\) and cos 60 = \(1\over 2\) By using the formula of sin 2A, sin 120 = 2 sin 60 cos 60 = 2 \(\times\) \(\sqrt{3}\over 2\) \(\times\) \(1\over 2\) \(\implies\)ย sin 120 = \(\sqrt{3}\over โฆ
Here you will learn what is the formula of tan 2A in terms of tan with proof and examples based on it. Letโs begin โ Tan 2A Formula : The formula of tan 2A is \(2 tan A\over 1 โ tan^2 A\) Proof : We have, tan (A + B) = \(tan A + tan โฆ
Here you will learn what is the formula of cos 2A in terms of sin and cos and also in terms of tan with proof and examples. Letโs begin โ Cos 2A Formula : (i) In Terms of Cos and Sin Given below are all the formulas for cos 2A. (i) cos 2A = \(cos^2 โฆ
Here you will learn what is the formula of sin 2A in terms of sin and cos and also in terms of tan with proof and examples. Letโs begin โ Sin 2A Formula (i) In Terms of Cos and Sin : Sin 2A = 2 sin A cos A Proof : We have, Sin (A โฆ
