AP EAMCET2002MathematicsQuadratic Equation
The maximum possible number of real roots of the equation x^ 5 5 -6 x^2-4 x+5=0 is
Options
- A0
- B3
- C4
- D5
Correct answer
B. 3
Step-by-step solution
Let f(x)=x^2-6 x^2-4 x+5 f(-x)=-x^5-6 x^2+4 x+5 Number of changes of sign in f(x) are 2 and number of changes of sign in f(-x) are 1 . By descarte's rule of signs Maximum number of +ve real roots are 2 and - ve real roots are 1. Maximum possible real roots are 3 .