Math, asked by matamsettiharini0000, 9 months ago

the domain of sec 5x is.​

Answers

Answered by Anonymous
6

Since secant is 1/cosine, the domain must avoid division by 0:

5x ≠ (2n - 1)π/2 for n = …, -3, -2, -1, 0, 1, 2, 3, … because for these values, cosine is 0

Thus, x ≠(2n - 1)π/10 (having divided both sides by 5)

Let u = 5x. Thus, du = 5 dx and dx = du/5:

the_integral_in_terms_of_u

Write sec u = 1/cos u and multiply by (cos u / cos u):

multiplying_by_cos_over_cos

The denominator is cosine squared:

cos^2

From sin2u + cos2u = 1, write cos2u as 1 - sin2u:

cos^2_is_1-sin^2

The integration becomes:

integration_sec_u

Let v = sin u meaning dv = cos u du:

v=sin_u

Write 1 - v2 as (1 - v)(1 + v):

difference_of_squares

Do a partial fraction expansion:

PFE

Find A and B:

finding_A_and_B

1/(1 - v2) becomes:

PFE_with_A=B=1/2

The integration becomes:

integration_of_sec_u_with_PFE

Evaluating each integral on the right-hand side separately.

Let w = 1 - v, dw = -dv:

with_w=1-v

The integral of dw/w is ln |w|:

ln|w|

Substitute back 1 - v for w:

sub_1-v_for_w

Substitute back sin u for v:

sin_u_for_v

Substitute back 5x for u:

sub_5x_for_u

Evaluating the second integral, this time w = 1 + v and dw = dv:

with_w=1-v

As before:

ln|w|

Substitute back 1 + v for w:

sub_1+v_for_w

Substitute back sin u for v:

sin_u_for_v

Substitute back 5x for u:

sub_5x_for_u

The integral of sec 5x becomes:

with_the_two_integrals

The difference of logarithms is the logarithm of a quotient:

multiply_1/5_by_1/2

1/2 times 1/5 gives 1/10. An indefinite integral includes a constant, C.

hope it helps u

plz mark BRAINLIEST

tannurao

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