1樓:學海無涯題作舟
2×4×6×8+16=400,
4×6×8×10+16=1936,
6×8×10×12+16=5776,
……(1)從上面的計算過程中,你發現了什麼規律?
(2)請用含有字母n的代數式表示這一規律,並說明它的正確性。
歸納:(1) 2×4×6×8+16=400=(4+2*8)^2
(2)4×6×8×10+16=1936=44^2=(4+2*8+3*8)^2
(3)6×8×10×12+16=5776=76^2=(4+2*8+3*8+4*8)^2
(4)8×10×12×14+16=116^2=(4+2*8+3*8+4*8+5*8)^2
(5)10×12×14×16+16=164^2=(4+2*8+3*8+4*8+5*8+6*8)^2
猜想(n) (2n)×(2n+2)×(2n+4)×(2n+6)+16=[4+2*8+3*8+4*8+5*8+6*8+...+(n+1)*8]^2
=[4+8n(n+3)/2]^2
=(4+4n^2+12n)^2
=4^2*[(n^2+3n)*(n^2+3n+2)+1]^2
=4^2*(n^2+3n+1^2
推導(2n)×(2n+2)×(2n+4)×(2n+6)+16=4^2*n*(n+1)*(n+2)*(n+3)+4^2
=4^2*[n*(n+1)*(n+2)*(n+3)+1]
=4^2*[n*(n+3)*(n+1)*(n+2)+1]
=4^2*[(n^2+3n)*(n^2+3n+2)+1]
=4^2*[(n^2+3n)*(n^2+3n+2)+1]
=4^2*[(n^2+3n)^2+2*(n^2+3n+1]
=4^2*(n^2+3n+1)^2
2樓:匿名使用者
歸納:(1) 2×4×6×8+16=400=(4+2*8)^2
(2)4×6×8×10+16=1936=44^2=(4+2*8+3*8)^2
(3)6×8×10×12+16=5776=76^2=(4+2*8+3*8+4*8)^2
(4)8×10×12×14+16=116^2=(4+2*8+3*8+4*8+5*8)^2
(5)10×12×14×16+16=164^2=(4+2*8+3*8+4*8+5*8+6*8)^2
猜想(n) (2n)×(2n+2)×(2n+4)×(2n+6)+16=[4+2*8+3*8+4*8+5*8+6*8+...+(n+1)*8]^2
=[4+8n(n+3)/2]^2
=(4+4n^2+12n)^2
=4^2*[(n^2+3n)*(n^2+3n+2)+1]^2
=4^2*(n^2+3n+1^2
推導(2n)×(2n+2)×(2n+4)×(2n+6)+16=4^2*n*(n+1)*(n+2)*(n+3)+4^2
=4^2*[n*(n+1)*(n+2)*(n+3)+1]
=4^2*[n*(n+3)*(n+1)*(n+2)+1]
=4^2*[(n^2+3n)*(n^2+3n+2)+1]
=4^2*[(n^2+3n)*(n^2+3n+2)+1]
=4^2*[(n^2+3n)^2+2*(n^2+3n+1]
數學題要過程分解因式,數學題因式分解 過程
數學題因式分解 過程 a b 4a b a b 2ab a b 2ab a b a b 根號a 根號b 根號a 根號b a b a 2 b 2 2 4a 2b 2 a 4 b 4 2a 2b 2 a 2 b 2 2 a 2 b 2 a 2 b 2 格式有點亂,請見諒!a b 4a b a b 2ab...
一道關於因式分解的數學題
2006x 2006y 1 x 3y 2006 試求2x 8xy 6y 的值 because,2006x 2006y 1,so that x y 1 2006 2x 8xy 6y 2 x 4xy 3y 2 x y x 3y 2 1 2006 2006 2 解 由2006x 2006y 1,得x y ...
初一因式分解競賽題
1.x 2 xy y 2 2 x 2 y 2 2 2xy x 2 y 2 xy 2 所以,原式 x 2 y 2 2 2xy x 2 y 2 xy 2 x 2 xy y 2 2 2.原式 x 1 x 2 2x 1 2x 3 90 x 1 2x 3 x 2 2x 1 90 2x 2 5x 3 2x 2 ...