If f (x) = px7 + qx3 + rx - 4 and f (-7) = 3 then the value of f (7) is... Help me please!

Question by Uchiha Sasuke

21/04/2017 at 08:40

Help me please!

Phan Thanh Tinh Coordinator 21/04/2017 at 08:48

f(7) = p.7⁷ + q.7³ + r.7 - 4 = -p.(-7)⁷ - q.(-7)³ - r.(-7) - 4

= -[p.(-7)⁷ + q.(-7)³ + r.(-7)] - 4 = -[f(-7) + 4] - 4

= -(3 + 4) - 4 = -7 - 4 = -11
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Khánh Lê Minh 23/04/2017 at 09:06

f(7) = p.77 + q.73 + r.7 - 4 = -p.(-7)7 - q.(-7)3 - r.(-7) - 4

= -[p.(-7)7 + q.(-7)3 + r.(-7)] - 4 = -[f(-7) + 4] - 4

= -(3 + 4) - 4 = -7 - 4 = -11
ichigodangyeu123 22/04/2017 at 20:58

What grade are you in?Uchiha Sasuke
Shizuka-chan 29/11/2019 at 08:41

What's your name?
Long Nguyen 10/04/2019 at 13:22

f (7) = p.7 7 + q.7 3 + r.7 - 4 = -p. (- 7) 7 - q. (- 7) 3 - r. (- 7) - 4

= - [p. (- 7) 7 + q. (- 7) 3 + r. (- 7)] - 4 = - [f (-7) + 4] - 4

= - (3 + 4) - 4 = -7 - 4 = -11
Thang Tran 24/10/2018 at 09:16

f(x) = px⁷ + qx³+ rx - 4 = x(px⁶ + qx²+ rx) - 4

set A = px⁶ + qx²+ rx

=> f(x) = x(A) - 4

with x = -7

=> f(-7) = -7(A) - 4 = 3 => A = -1

with x = 7

=> f(7) = 7(A) - 4 = 7(-1) - 4 =11
băng đỗ 09/09/2018 at 08:05

= - 11

chúc bạn hok tốt
Uchiha Sasuke 24/04/2017 at 07:56

I'm in grade 7
tuanhotboy 22/04/2017 at 20:59

f(7) = p7⁷ + q7³+ r7 - 4 ; f(-7)= p (-7)⁷ + q (-7)³ + r(-7) - 4

f(7) + f(-7) = -8 => f(7) = -11
Uchiha Sasuke 21/04/2017 at 08:58

Thank you!