6(х-1) = 9,4 - 1,7х 3,5 - 9а = 2(0,5а - 4 ) - id2044353620220104 от Tony271 04.01.2022 16:05

Question

Алгебра: 6(х-1) = 9,4 - 1,7х 3,5 - 9а = 2(0,5а - 4 )

Tony271 · Accepted Answer

task/27281836

1)
tg(-α)*ctgα+sin²(-α) , если tgα=-3/4
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tg(-α)*ctgα+sin²(-α) = -tgα*ctgα+sin²α= -1 + sin²α = -(1-sin²α) = - cos²α =
- ( 1/(1+tg²α) = -1/(1 +(-3/4)² ) = -16/25 .

2)
(sinα*cosα)/(sin^2α-cos^2α) , если tgα=3/2
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(sinα*cosα)/(sin²α-cos²α) = (1/2)*sin2α / (- cos2α) = -(1/2)*tg2α =
- tgα / (1+tg²α) = -(3/2) /(1 +(3/2)²) = - 6/13 .

3)
√5 *sina , если tgα=2 ,α ∈ 3 четверти
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α ∈ 3 четверти ⇒ sinα < 0
√5 *sinα =√5 *(- √(1 -cos²α) )= - √5 *√(1 - 1/(1+tg²α) ) = - √5 *√(1 - 1/(1+2²) )=
- √5 *√(1 - 1/5) = - √5 *√(4/5) = - √5 *2/√5 = - 2.

4)
tg^3a+ctg^3a , если tga + ctga=5
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tg³α+ctg³α= (tgα+ctgα)³ -3tgα*ctgα(tgα+ctgα) = (tgα+ctgα)³ -3*1*(tgα+ctgα)=
5³ -3*5 =125 -15 =110.

6(х-1) = 9,4 - 1,7х 3,5 - 9а = 2(0,5а - 4 )

MOGZ ответил

6(х-1) = 9,4 - 1,7х
3,5 - 9а = 2(0,5а - 4 )