You need to differentiate the function y with respect to x such that:
`(dy)/(dx) = (2x^2+4x+3)' =gt (dy)/(dx) = 4x + 4`
You need to multiply by dx both sides such that:
`(dy) = (4x + 4)(dx) `
You need to evaluate dy at x=4 and dx = 0.3, hence you should substitute 4 for x and 0.3...
(The entire section contains 2 answers and 133 words.)