The tangent to 
through (1, 1, 1) must be perpendicular to the normal vectors to the surfaces 
and 
at that point.
Let 
. Then is the level curve 
. Recall that the gradient vector is perpendicular to level curves; we have
so that the gradient of 
at (1, 1, 1) is
For the surface , we have
so that 
. We can obtain a vector normal to by taking the cross product of the partial derivatives of 
, and evaluating that product for 
:
Now take the cross product of the two normal vectors to and :
The direction of vector (24, 8, -8) is the direction of the tangent line to at (1, 1, 1). We can capture all points on the line containing this vector by scaling it by 
. Then adding (1, 1, 1) shifts this line to the point of tangency on . So the tangent line has equation
-16 i think is the correct anwser because you take the old number then subtract the new number then divide the old one then multiply by 100
factor out 8a from the expression 8a(5a-4)
Answer:
I hope this helps. If I misunderstood the question let me know
Step-by-step explanation:
1. When dividing a negative by a negative, your answer would be positive.
2. When dividing a negative by a positive, your answer will be negative.
3. When dividing a positive by a negative,your answer will be negative.
