NDA2018MathematicsFunctionsActual
If f: R S defined by f(x)=4 x-3 x+1 is onto, then what is S equal to?
Options
- A[-5,5]
- B(-5,5)
- C(-4,6)
- D[-4,6]
Correct answer
D. [-4,6]
Step-by-step solution
f(x)=4 x-3 x+1 To find range of this function, we have to find maximum and minimum values. We know, for a + b + c , max value is a ^2+ b ^2 + c and minimum value is - a ^2+ b ^2 + c . aligned Maximum value & = (4)^2+(-3)^2 +1 & = 16+9 +1=5+1=6 aligned Minimum value =- 16+9+1 =-5+1=-4 Range, S [-4,6]