Toán Lớp 7: cho hàm số y=f(x0=4x^2-3x+1 tính f(1/2),f(10,f(0),f(2,3),f(2)

Question

Toán Lớp 7:  cho hàm số y=f(x0=4x^2-3x+1 tính f(1/2),f(10,f(0),f(2,3),f(2)

lantrungbach · Answer

y = f(x)   - V&igrave;: f(x) = 4x^2 - 3x + 1   => f(1/2) = 4x^2 - 3x + 1   = 4 &times; (1/2)^2 - 3 &times; 1/2 + 1   = 4 &times; 1/4 - 3/2 + 1   = 1 - 3/2 + 1   = 1/2   => f(1/2) = 1/2                                                                        => f(1) = 4 &times; 1^2 - 3 &times; 1 + 1   = 4 &times; 1 - 3 + 1   = 4 - 3 + 1   = 1 + 1   = 2   => f(1) = 2                                                                           => f(0) = 4 &times; 0^2 - 3 &times; 0 + 1   = 4 &times; 0 - 0 + 1   = 0 - 0 + 1   = 1   => f( 0 ) = 1                                                                            f( 2,3 ) = 4 &times; ( 2,3 )^2 - 3 &times; 2,3 + 1   = 4 &times; 5,29 - 6,9 + 1   = 21,16 - 6,9 + 1   = 15,26   => f( 2,3 ) = 15,26                                                                               f(2) = 4 &times; 2^2 - 3 &times; 2 + 1   = 4 &times; 4 - 6 + 1   = 16 - 6 + 1   = 11   => f(2) = 11   @Tina

mocmien87 · Answer

Lời giải chi tiết:     y=f(x)=4x^2-3x+1   $ huge{.}$f(1/2)=4.(1/2)^2-3.(1)/2+1=1-3/2+1=-1/2+1=1/2   $ huge{.}$f(10)=4.10^2-3.10+1=400-30+1=370+1=371   $ huge{.}$f(0)=4.0^2-3.0+1=0-0+1=0+1=1   $ huge{.}$f(2/3)=4.(2/3)^2-3.(2)/3+1=16/9-2+1=-2/9+1=7/9   $ huge{.}$f(2)=4.2^2-3.2+1=16-6+1=10+1=11