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Answer:
Solutions: x = +\- 5i or x = +\- sqrt(5)
Discussion:
Factor x^4 - 25:
x^4 - 25 = (x^2+5) (x^2-5) => factor x^2 - 5
x^4 - 25 = (x^2+5)(x + sqrt(5)) (x - sqrt(5)) => factor x^2 + 5
x^4 = 25 = (x +5i)(x-5i) (x + sqrt(5)) (x - sqrt(5))
Hence the solutions are
x = +\- 5i and x = +\- sqrt(5)
Thank you,
MrB
Answer:
D
Step-by-step explanation:
Answer:
100
Step-by-step explanation:
2:3:5
20:30:50
20 + 30 + 50 = 50 + 50 = 100
Answer:
(d).
Step-by-step explanation:
sin² β + cos² β = 1
cos (α + β) = cos α cos β - sin α sin β
cos α = √(1 - ) = 21 / 29
cos β = 12 / 13
sin β = √(1 - ) = 5 / 13
sin α = 20 / 29
cos (α + β) = × - × =