Question

cho hàm số f(x)=a.x²+b.x⁴+x+3+11.biết f(-2)=3. hỏi vậy f(2) thì bằng bao nhiêu?

Answer 1

Ta có \(f\left(x\right)=ax^2+bx^4+x+3+11\)

\(=>f\left(-2\right)=a\left(-2\right)^2+b\left(-2\right)^4+\left(-2\right)+3+11=3\)

\(=>f\left(-2\right)=4a+16b+12=3\)

Ta có \(f\left(2\right)=a\left(2^2\right)+b\left(2^4\right)+2+3+11\)

\(=>f\left(2\right)=4a+16b+16\)

\(=>f\left(2\right)=4a+16b+12+4\)

Mà \(f\left(-2\right)=4a+16b+12=3\)

\(=>f\left(2\right)=4a+16b+12+4\)

\(=>f\left(2\right)=3+4\)

\(=>f\left(2\right)=7\)