Question

(t²+2t).(t²-2t) =45
Equaçao biquadrada

Answer 1

t²*t²-t²*2t+2t*t²+4t²=45

$t^{4} +4t^{2}=45$

$t^{4}+4t^{2}-45=0$

Chamamos t² = x

x²+4x-45 = 0

Resolvendo por Bhaskara:

X' = -9 e X''=5

t² = 5

t = +-√5

t² = -9

t = √-9 t∉R

Resposta {+-√5}

Answer 2

[ ( t )2 ] 2 - ( 2t ) 2 = 45

( t ) 4 - 4 t2 - 45 = 0
chamar t2 de x
x2 - 4x - 45 = 0
∆ = 16 + 180
∆ = 196

X1 = ( 4 + 14 ) / 2
X1 = 18 / 2
X1 = 9

X2 = ( 4 - 14 ) / 2
X2 = - 14 / 2
X2 = - 7 ( não serve )

resposta final

T = √9
T = + 3 e - 3