Final answer:
The value of dy/dt at x=1 and y=x²+3, when dx/dt=4, is 8.
Step-by-step explanation:
To find dy/dt at x=1 and y=x²+3 if dx/dt=4, we need to differentiate y with respect to t. Since y = x²+3, we first find dy/dx by differentiating x²+3 with respect to x, which gives us 2x. Then, we multiply by dx/dt, which is 4, to get dy/dt = 8x. Substituting x=1, we get dy/dt = 8.