NDA2021MathematicsContinuity and DifferentiabilityActual
If the function f(x)= array ll a+b x, & x 1 5, & x=1 b-a x, & x 1 array . is continuous, then what is the value of (a+b) ?
Options
- A5
- B10
- C15
- D20
Correct answer
A. 5
Step-by-step solution
f(x)= array lc a+b x, & x 1 5, & x=1, is continuous b-a x, & x 1 array . aligned & _ x 1⁻ f(x)= _ x 1⁺ f(x)=f(1) & _ x 1⁻ (a+b x)= _ x 1⁺ (b-a x)=5 aligned a+b=5 (i) and b-a=5 . (ii) From (i) and (ii) b=5 and a=0 a+ b =0+5=5