How i solve the introduction of trigonometry of class 10 ncert . Find the best way to solve the trigonometry question of exercise 8.4 question number 1 easily, please help me to solve the question in a easiest way.Express the trigonometric ratios sin A, sec A and tan A in terms of cot A
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To convert the given trigonometric ratios in terms of cot functions, use trigonometric formulas
We know that,
cosec2A – cot2A = 1
cosec2A = 1 + cot2A
Since cosec function is the inverse of sin function, it is written as
1/sin2A = 1 + cot2A
Now, rearrange the terms, it becomes
sin2A = 1/(1+cot2A)
Now, take square roots on both sides, we get
sin A = ±1/(√(1+cot2A)
The above equation defines the sin function in terms of cot function
Now, to express sec function in terms of cot function, use this formula
sin2A = 1/ (1+cot2A)
Now, represent the sin function as cos function
1 – cos2A = 1/ (1+cot2A)
Rearrange the terms,
cos2A = 1 – 1/(1+cot2A)
⇒cos2A = (1-1+cot2A)/(1+cot2A)
Since sec function is the inverse of cos function,
⇒ 1/sec2A = cot2A/(1+cot2A)
Take the reciprocal and square roots on both sides, we get
⇒ sec A = ±√ (1+cot2A)/cotA
Now, to express tan function in terms of cot function
tan A = sin A/cos A and cot A = cos A/sin A
Since cot function is the inverse of tan function, it is rewritten as
tan A = 1/cot A