# A-Math – Trigonometry

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## Additional Math – Important Trigonometry Rules

Summary of Some of the  Important Trigonometry Rules. This is not exhaustive the links for  the complete list of Trigonometric [...]

By |2021-05-06T12:52:13+08:00May 6th, 2021|A-Math - Trigonometry|

$latex \displaystyle \cot \left( {\frac{x}{2}} \right)-2\cos \left( {\frac{x}{2}} \right)=0$ Convert cotangent into cosine divided by sine. $latex \displaystyle \frac{{\cos \left( [...] By |2021-04-05T22:51:56+08:00April 5th, 2021|A-Math - Trigonometry| ## Additional Math – Trigonometry – Prove Identities involving Cot A and TanA$latex \displaystyle \ \frac{{\cot A-\tan A}}{{\cot A+\tan A}}latex \displaystyle (\cot A-\tan A)\div (\cot A+\tan A)$Change tan A to [...] By |2020-02-01T22:04:34+08:00February 1st, 2020|A-Math - Trigonometry| ## Additional Math – Trigonometry – The most challenging question we came across – mid year 2019 Exam While preparing students for the mid year exam 2019, I stumbled upon a very challenging question, I have never came [...] By |2019-05-16T13:06:55+08:00May 16th, 2019|A-Math - Trigonometry| ## Additional Math – Differentiation – Equations with cot x and cosec x$latex \displaystyle y={{\cot }^{2}}x-5+\cos ecx$It is difficult to differentiate cot x and cosec x directly. You need to change [...] By |2018-12-23T11:26:43+08:00December 23rd, 2018|A-Math - Differentiation, A-Math - Trigonometry| ## Additional Math – Trigonometry – Prove Identities of (tan x-1)/(tan x+1) RHS$latex \displaystyle \frac{{\tan x-1}}{{\tan x+1}}$Change tan x to sin x /cos x and 1 to cos x /cos [...] By |2018-09-14T11:24:29+08:00September 14th, 2018|A-Math - Trigonometry| ## Additional Math – Trigonometry – Prove the Identity Cos x/ (1- Sin x) = Tan x + Sec x$latex \displaystyle \frac{{\cos x}}{{1-\sin x}}=\tan x + \sec x$The rule of thumb is to always prove from the side [...] By |2018-07-09T11:01:24+08:00June 20th, 2018|A-Math - Trigonometry| ## Additional Math – Trigonometry – How to derive Sine Half Angle. Use the Cosine Double Angle Formula again, (NOT SINE DOUBLE ANGLE) to help derive Cosine 1/2 Angle.$latex \displaystyle \text{cos}\ [...]

By |2018-01-09T04:13:34+08:00January 9th, 2018|A-Math - Trigonometry|

Use the Cosine Double Angle Formula (found in Formula List) to help derive Cosine 1/2 Angle. $latex \displaystyle \text{cos}\ 2A=2{{\cos [...] By |2018-01-09T04:19:42+08:00January 3rd, 2018|A-Math - Trigonometry| ## Additional Math – Trigonometry – Proving Identities Sunday Additional Math Group Tuition at Woodlands - prove identities trigonometry$latex \displaystyle \text{LHS}latex \displaystyle {{\sec }^{4}}x-{{\tan [...]

By |2017-11-15T13:14:30+08:00August 29th, 2017|A-Math - Trigonometry|