F(1/2)=2*(1/2)^2-3
F(0,5)=2*(0,5)^-3
F(0,5)=2*0,25-3
F(0,5)=-2,5
F(2)=2*2^2-3
F(2)=8-3
F(2)=5
3^(3x + 1) + 8*3^(2x) - 3^(x + 1) = 0
Пусть 3^x = t, тогда
3t^3 + 8t^2 - 3t = 0
t (3t^2 + 8t - 3) = 0
1) t= 0
3^x = 0
x ∉ R
2)
3t^2 + 8t - 3 = 0
D = 64 + 36 = 100 = 10^2
t1 = ( - 8 + 10)/6 = 2/6 = 1/3;
t2 = ( - 8 - 10)/6 = - 18/6 = - 3
3^x = 1/3
3^x = 3^(-1)
x = - 1
3^x = - 3
x ∉ R
Ответ
- 1
2 * 4^2 - 0.5 * (-2) + 6 = 2 * 16 + 1 + 6 = 32 + 1 + 6 = 39