Advertisements
Advertisements
प्रश्न
Find the derivative of the following function (it is to be understood that a, b, c, d, p, q, r and s are fixed non-zero constants and m and n are integers):
`(sin(x + a))/ cos x`
Advertisements
उत्तर
Let f(x) = `(sin (x + a))/(cos x)`
By quotient rule,
f'(x) = `(cos x d/dx [sin (x + a)] - sin(x + a) d/dx cos x)/cos^2 x`
f'(x) = `(cos x d/dx [sin (x + a)] - sin(x + a) (-sin x))/cos^2 x` ...(i)
Let g(x) = sin (x + a) Accordingly. g(x + h) = sin (x + h + a)
By first principle,
g'(x) = `lim_(h->0) (g(x + h) - g(x))/h`
= `lim_(h->0)1/h [sin (x + h + a) -sin (x + a)]`
= `lim_(h->0)1/h [2 cos ((x + h + a + x + a)/2) sin ((x + h + a - x - a)/2)]`
= `lim_(h->0)1/h [2 cos ((2x + 2a + h)/2) sin(h/2)]`
= `lim_(h->0) [cos ((2x + 2a + h)/2) {sin (h/2)/(h/2)}]`
= `lim_(h->0) cos ((2x + 2a + h)/2) lim_(h->0){sin (h/2)/(h/2)}` `["As" h->0=>h/2->0]`
= `(cos (2x + 2a)/2) xx 1` `[lim_(h->0) (sin h)/h = 1]`
= cos (x + a)
From (i) and (ii) we obtain
f'(x) = `(cosx. cos (x + a) + sin x sin (x + a))/cos^2x`
= `(cos (x + a - x))/cos^2 x`
= `(cos a)/cos^2 x`
APPEARS IN
संबंधित प्रश्न
Find the derivative of x2 – 2 at x = 10.
Find the derivative of the following function (it is to be understood that a, b, c, d, p, q, r and s are fixed non-zero constants and m and n are integers):
(ax + b) (cx + d)2
Find the derivative of the following function (it is to be understood that a, b, c, d, p, q, r and s are fixed non-zero constants and m and n are integers):
`(ax + b)/(cx + d)`
Find the derivative of the following function (it is to be understood that a, b, c, d, p, q, r and s are fixed non-zero constants and m and n are integers):
`(px^2 +qx + r)/(ax +b)`
Find the derivative of the following function (it is to be understood that a, b, c, d, p, q, r and s are fixed non-zero constants and m and n are integers):
x4 (5 sin x – 3 cos x)
Find the derivative of the following function at the indicated point:
Find the derivative of the following function at the indicated point:
2 cos x at x =\[\frac{\pi}{2}\]
\[\frac{x^2 + 1}{x}\]
Differentiate each of the following from first principle:
e−x
Differentiate of the following from first principle:
x cos x
Differentiate each of the following from first principle:
\[\sqrt{\sin 2x}\]
Differentiate each of the following from first principle:
x2 sin x
\[\frac{( x^3 + 1)(x - 2)}{x^2}\]
\[\frac{a \cos x + b \sin x + c}{\sin x}\]
If for f (x) = λ x2 + μ x + 12, f' (4) = 15 and f' (2) = 11, then find λ and μ.
For the function \[f(x) = \frac{x^{100}}{100} + \frac{x^{99}}{99} + . . . + \frac{x^2}{2} + x + 1 .\]
x3 sin x
xn tan x
(x3 + x2 + 1) sin x
x5 ex + x6 log x
(1 +x2) cos x
\[e^x \log \sqrt{x} \tan x\]
\[\frac{x^2 \cos\frac{\pi}{4}}{\sin x}\]
(2x2 − 3) sin x
Differentiate each of the following functions by the product rule and the other method and verify that answer from both the methods is the same.
(3x2 + 2)2
Differentiate each of the following functions by the product rule and the other method and verify that answer from both the methods is the same.
(3 sec x − 4 cosec x) (−2 sin x + 5 cos x)
\[\frac{a x^2 + bx + c}{p x^2 + qx + r}\]
\[\frac{x}{1 + \tan x}\]
Write the value of \[\lim_{x \to c} \frac{f(x) - f(c)}{x - c}\]
Write the value of \[\frac{d}{dx} \left\{ \left( x + \left| x \right| \right) \left| x \right| \right\}\]
Mark the correct alternative in of the following:
If \[y = \sqrt{x} + \frac{1}{\sqrt{x}}\] then \[\frac{dy}{dx}\] at x = 1 is
Mark the correct alternative in of the following:
If f(x) = x sinx, then \[f'\left( \frac{\pi}{2} \right) =\]
Find the derivative of f(x) = tan(ax + b), by first principle.
(ax2 + cot x)(p + q cos x)
Let f(x) = x – [x]; ∈ R, then f'`(1/2)` is ______.
