QJEEAdv24Ma6ce2: JEE Advanced 2024 Mathematics - Class 11 JEEAdv24Ma6ce2 Solution: Let be a polynomial with real coefficients such that . Suppose…
Let f(x)=x4+ax3+bx2+c be a polynomial with real coefficients such that f(1)=−9. Suppose that i3 is a root of the equation 4x3+3ax2+2bx=0, where i=−1. If α1,α2,α3, and α4 are all the roots of the equation f(x)=0, then ∣α1∣2+∣α2∣2+∣α3∣2+∣α4∣2 is equal to ____________.
Step-by-Step Verified Solution
f(1)=1+a+b+c=−9⇒a+b+c=−10.... (i)
amp;4x3+3ax2+2bx=0 roots are 3i,−3i,0amp;⇒4x2+3ax+2b=0amp;⇒a=0&42b=(3i)(−3i)amp;b=6 use a,b in (1) ⇒c=−16amp;⇒f(x)=x4+6x216=0amp;(x2+8)(x2−2)=0amp;⇒x=±8i,±2⇒∣α1∣2+∣α2∣2+∣α3∣2+∣α4∣2=20amp;lt;3i−3i