Preparing for CDS Elementary Mathematics is a challenging task for the aspirants. Around 10-15 questions were asked from trigonometry section in CDS 2016. Thus, weightage of trigonometry in UPSC CDS exam is around 12-15%, according to CDS previous years’ papers. Candidates should focus more on identity type based questions rather than direct formulae based questions for scoring better in CDS.
Solving questions based on trigonometry ratios should be given first priority while attempting CDS Elementary Mathematics Paper. There are some more tips to excel the preparation for trigonometry based questions.
Pythagoras Theorem- You must be knowing about it. Perpendicular, Base and Hypotenuse, where Perpendicular is always opposite to the angle theta ‘Θ’.
In the above diagram, BC is the perpendicular and AC is the base of right-angled triangle ABC. Learn the order of trigonometry ratios. Here’s the secret mantra- “Pandit Badri Prasad Har Har Bhole” (PBPHHB)
Sin Cos Tan
P B P
H H B
Cosec Sec Cot
Apart from the given tips for CDS 2018 preparation, it is important for you to learn some of the trigonometric identities and ratios which is given below:
Negative of a Function:
Angle of Elevation: Let AB be a tower/pillar/shell/minar/pole) on the base BC and C is the person looking at the top of AB.
The angle ACB, made by hypotenuse AC and base BC is called the angle of elevation.
Angle of Depression: If observer is at Q and is viewing an object R on the ground SR, then angle between PQ and QR is the angle of depression.
Numerically, angle of elevation is equal to the angle of depression. In the following table, the value of ‘Θ’ is mentioned-
*The article might have information for the previous academic years, please refer the official website of the exam.