a. Practically speaking, you compute the differential in much the same way you compute a derivative via implicit differentiation, but you omit the variable with respect to which you are differentiating.
Aside: Compare this to what happens when you differentiate both sides with respect to some other independent parameter, say 
:
b. This is just a matter of plugging in 
and 
.
Answer:
It's the one right under the first one
It is 7/42 that is the answer
Answer:
4.05d+0.1i−4.2
Step-by-step explanation:
Let's simplify step-by-step.
1.6i+
3/
4
d−3(
1
/2
i−1.1d)−4.2
Distribute:
=1.6i+
3/
4
d+(−3)(
1/
2
i)+(−3)(−1.1d)+−4.2
=1.6i+
3/
4
d+
−3/
2
i+3.3d+−4.2
Combine Like Terms:
=1.6i+
3/
4
d+
−3/
2
i+3.3d+−4.2
=(
3/
4
d+3.3d)+(1.6i+
−3/
2
i)+(−4.2)
=4.05d+0.1i+−4.2
Hope it helped!
