(i) We have,

Now,

Put t = 0

f(0) = 4(0)² - 3(0) + 6

= 4(0) - 3(0) + 6

= 0 – 0 + 6

= 6

Hence,

f(0) = 6

(ii) We have,

Now,

Put t = 4

f(4) = 4(4)² -3(4) + 6

= 4(16) - 3(4) + 6

= 64 – 12 + 6

= 58

Hence,

f(4) = 58

(iii) We have,

Now,

Put t = -5

f(-5)=4(-5)² - 3(-5) + 6

= 4(25) - 3(-5) + 6

= 100 + 15 + 6

= 121

Hence,

f(0) = 6