Prove
sec2x - tan2x = tan(45-x)
Pls Help!!!TQ

Step-by-step explanation:

sec(2x) − tan(2x)

Write in terms of sine and cosine:

1/cos(2x) − sin(2x)/cos(2x)

(1 − sin(2x)) / cos(2x)

Use double angle formulas:

[ 1 − 2 tan x / (1 + tan²x) ] / [ (1 − tan²x) / (1 + tan²x) ]

Multiply by reciprocal:

[ 1 − 2 tan x / (1 + tan²x) ] × [ (1 + tan²x) / (1 − tan²x) ]

Distribute 1 + tan²x:

(1 + tan²x − 2 tan x) / (1 − tan²x)

Factor:

(1 − tan x)² / ((1 − tan x) (1 + tan x))

Simplify:

(1 − tan x) / (1 + tan x)

Rewrite using 1 = tan(45°):

(tan(45°) − tan x) / (tan(45°) + tan x)

Use angle difference formula:

tan(45° − x)

it costs $20 to interview each person for a survey. find the cost to obtain a +- 3% margin of error.

step-by-step explanation:

copy and paste, put it in google

3. (5x + 1) - (-10x + 6)

simplify the answer choice. combine like terms. remember to distribute the negative to the terms inside the second parenthesis. also remember that two negatives = one positive, and one of each sign = negative.

- (-10x + 6) = + 10x - 6

simplify. combine like terms:

5x + 1 + 10x - 6

5x + 10x + 1 - 6

15x - 5

∴ it is your answer

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