If f(x) = 3x + 5, g(x) = 6x – 1, then find(i) (f + g) (x)(ii) (f –

1.	If f(x) = 3x + 5, g(x) = 6x – 1, then find(i) (f + g) (x)(ii) (f – g) (2)(iii) (fg) (3)(iv) (f/g) (x) and its domain
Answer» f(x) = 3x + 5, g (x) = 6x – 1 (i) (f + g) (x) = f (x) + g (x) = 3x + 5 + 6x – 1 = 9x + 4 (ii) (f – g) (2) = f(2) – g(2) = [3(2) + 5] – [6(2) – 1] = 6 + 5 – 12 + 1 = 0 (iii) (fg) (3) = f (3) g(3) = [3(3) + 5] [6(3) – 1] = (14) (17) = 238 (iv) \((\frac fg)x=\frac{f(x)}{g(x)}=\frac{3x+5}{6x-1}, x\neq \frac16\) Domain = R - \(\{\frac16\}\)

If f(x) = 3x + 5, g(x) = 6x – 1, then find(i) (f + g) (x)(ii) (f – g) (2)(iii) (fg) (3)(iv) (f/g) (x) and its domain

Answer»

f(x) = 3x + 5, g (x) = 6x – 1

(i) (f + g) (x) = f (x) + g (x)

= 3x + 5 + 6x – 1

= 9x + 4

(ii) (f – g) (2) = f(2) – g(2)

= [3(2) + 5] – [6(2) – 1]

= 6 + 5 – 12 + 1

= 0

(iii) (fg) (3) = f (3) g(3)

= [3(3) + 5] [6(3) – 1]

= (14) (17)

= 238

(iv) \((\frac fg)x=\frac{f(x)}{g(x)}=\frac{3x+5}{6x-1}, x\neq \frac16\)

Domain = R - \(\{\frac16\}\)