Question

Grade 11 Functions - Struggling to answer this question in full, please help me by providing an answer.
The cost, c(x) in dollars in per hour of running a certain fishing boat is modeled by the function c(x)= 0.9x^2 - 18.1x + 135.1, where x is the speed in km/hour/ At what approximate speed should the boat travel to achieve minimum cost?

Answer 1

Step-by-step explanation:

c(x)= 0.9x^2 - 18.1x + 135.1

a = 0.9 , b = -18.1

the function becoming minimum for

x = -b/2a

x = (18.1)/(1.8)

x= 10.05

=> c(10.05)= 0.9(10.05)²- 18.1(10.05) +135.1

= 0.9(101.0025)-181.905+135.1

=90.90225 - 181.905+135.1

= 44.09725 km/h