Let y=tan(2x+5).

Find the differential dy when x=1 and dx=.3
Find the differential dy when x=1 and dx=.6

well, since

dy = 2sec^2(2x+5) dx
just plug in your numbers

I can't figure out the first one???

Steve

Read second post.

To find the differential dy when x=1 and dx=.3, we can use the derivative of the function y=tan(2x+5). The derivative of tan(x) is sec^2(x), so the derivative of y with respect to x is dy/dx = sec^2(2x+5).

Now, to find the differential dy, we can use the formula: dy = (dy/dx) * dx.

When x=1 and dx=.3, we substitute these values into the derivative expression:

dy/dx = sec^2(2x+5)
dy/dx = sec^2(2(1)+5)
dy/dx = sec^2(7)

Now, substitute dy/dx = sec^2(7) and dx = .3 into the differential formula:

dy = (sec^2(7)) * .3

Calculating the value using a scientific calculator or programming language, we find:

dy ≈ (2.853) * .3
dy ≈ 0.856

So, when x=1 and dx=.3, the differential dy is approximately 0.856.

To find the differential dy when x=1 and dx=.6, we follow the same procedure. First, calculate the derivative expression:

dy/dx = sec^2(2(1)+5)
dy/dx = sec^2(7)

Now, substitute dy/dx = sec^2(7) and dx = .6 into the differential formula:

dy = (sec^2(7)) * .6

Calculating the value:

dy = (2.853) * .6
dy ≈ 1.712

So, when x=1 and dx=.6, the differential dy is approximately 1.712.