LA4 marksYear: 2020MediumCBSE Class 10
polynomialszeroesdivision
Question
Obtain other zeroes of the polynomial
f(x)=2x4+3x3−5x2−9x−3
if two of its zeroes are 3 and −3. Solution
1
∵3 and −3 are zeroes of f(x). ∴(x−3) and (x+3) are factors of f(x). ∴x2−3 is a factor of f(x) +1 mark2
q(x)=x2−32x4+3x3−5x2−9x−3=2x2+3x+1
+1 mark3
For zeroes q(x)=0: 2x2+3x+1=0⇒(x+1)(2x+1)=0. x=−1,−21
+1 mark4
∴ Remaining zeroes are −1 & −21
+1 mark