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 `2x - 3/4`
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+ q) (r/s + s)`
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):
(ax + b)n
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)
Find the derivative of f (x) = cos x at x = 0
\[\frac{2x + 3}{x - 2}\]
Differentiate of the following from first principle:
eax + b
Differentiate of the following from first principle:
(−x)−1
Differentiate of the following from first principle:
sin (2x − 3)
Differentiate each of the following from first principle:
\[e^\sqrt{2x}\]
tan (2x + 1)
tan 2x
\[\cos \sqrt{x}\]
ex log a + ea long x + ea log a
\[\frac{2 x^2 + 3x + 4}{x}\]
\[\frac{(x + 5)(2 x^2 - 1)}{x}\]
For the function \[f(x) = \frac{x^{100}}{100} + \frac{x^{99}}{99} + . . . + \frac{x^2}{2} + x + 1 .\]
x2 ex log x
xn tan x
(x3 + x2 + 1) sin x
\[\frac{2^x \cot x}{\sqrt{x}}\]
(x sin x + cos x ) (ex + x2 log x)
(2x2 − 3) sin x
\[\frac{x + e^x}{1 + \log x}\]
\[\frac{a x^2 + bx + c}{p x^2 + qx + r}\]
\[\frac{1}{a x^2 + bx + c}\]
\[\frac{e^x}{1 + x^2}\]
\[\frac{x \sin x}{1 + \cos x}\]
\[\frac{\sin x - x \cos x}{x \sin x + \cos x}\]
\[\frac{{10}^x}{\sin x}\]
\[\frac{4x + 5 \sin x}{3x + 7 \cos x}\]
\[\frac{a + b \sin x}{c + d \cos x}\]
\[\frac{p x^2 + qx + r}{ax + b}\]
If \[\frac{\pi}{2}\] then find \[\frac{d}{dx}\left( \sqrt{\frac{1 + \cos 2x}{2}} \right)\]
Mark the correct alternative in of the following:
If\[y = 1 + \frac{x}{1!} + \frac{x^2}{2!} + \frac{x^3}{3!} + . . .\]then \[\frac{dy}{dx} =\]
Mark the correct alternative in of the following:
If \[f\left( x \right) = x^{100} + x^{99} + . . . + x + 1\] then \[f'\left( 1 \right)\] is equal to
Mark the correct alternative in of the following:
If f(x) = x sinx, then \[f'\left( \frac{\pi}{2} \right) =\]
Find the derivative of 2x4 + x.
