K kr73114 Member Joined Aug 6, 2009 Messages 373 Gender Male HSC 2011 Dec 17, 2009 #1 ie) 3b^4-13b^2-2=0
addikaye03 The A-Team Joined Nov 16, 2006 Messages 1,267 Location Albury-Wodonga, NSW Gender Male HSC 2008 Dec 17, 2009 #2 kr73114 said: ie) 3b^4-13b^2-2=0 Click to expand... IF you need, make it look nicer Let u=b^2 3u^2-13u-2=0 It won't fartorise nicely so quadratic formula: u=[13+- sqrt( 13^2+24)]/ 6 Then Resubstitute for u [b^2] b=+-sqrt {13+- sqrt( 13^2+24)]/ 6}
kr73114 said: ie) 3b^4-13b^2-2=0 Click to expand... IF you need, make it look nicer Let u=b^2 3u^2-13u-2=0 It won't fartorise nicely so quadratic formula: u=[13+- sqrt( 13^2+24)]/ 6 Then Resubstitute for u [b^2] b=+-sqrt {13+- sqrt( 13^2+24)]/ 6}
adomad HSC!! Joined Oct 10, 2008 Messages 543 Gender Male HSC 2010 Dec 17, 2009 #3 this type of problem is called equations reducible to a quadratic.
K kr73114 Member Joined Aug 6, 2009 Messages 373 Gender Male HSC 2011 Dec 21, 2009 #4 so what would be the solutions for b?
C Cazic Member Joined Aug 26, 2009 Messages 166 Gender Male HSC 2011 Dec 21, 2009 #5 addikaye03 gave them in his last line.