Question and Answers Forum

All Questions      Topic List

Algebra Questions

Previous in All Question      Next in All Question      

Previous in Algebra      Next in Algebra      

Question Number 202605 by hardmath last updated on 30/Dec/23

Commented by mr W last updated on 30/Dec/23

what do you mean when you write  max_(=b)  min_(=a)  (...) ?

whatdoyoumeanwhenyouwritemax=bmin=a(...)?

Commented by hardmath last updated on 30/Dec/23

dear professor,    In the given expression, the maximum value is for b, and the minimum value is for a

dearprofessor,In the given expression, the maximum value is for b, and the minimum value is for a

Commented by mr W last updated on 30/Dec/23

x=±1

x=±1

Answered by mr W last updated on 30/Dec/23

we replace a, b, x with x, y, k.  f(x,y)=x^2 −2xy−y^2 −2kx+10ky     =(x−y−k)^2 −2y^2 +8ky−k^2   f_(min) is when x−y−k=0  f(x,y)=−(y+x−5k)^2 +2x^2 −12kx+25k^2   f_(max)  is when x+y−5k=0  ⇒x=3k, y=2k  (3k)^2 −2(3k)(2k)−(2k)^2 −2k(3k)+10k(2k)=7  k^2 =1  ⇒k=±1

wereplacea,b,xwithx,y,k.f(x,y)=x22xyy22kx+10ky=(xyk)22y2+8kyk2fminiswhenxyk=0f(x,y)=(y+x5k)2+2x212kx+25k2fmaxiswhenx+y5k=0x=3k,y=2k(3k)22(3k)(2k)(2k)22k(3k)+10k(2k)=7k2=1k=±1

Commented by hardmath last updated on 30/Dec/23

cool dear professor thank you

cooldearprofessorthankyou

Terms of Service

Privacy Policy

Contact: info@tinkutara.com