We want to find a scalar function
such that
.
So we need to have
Integrating both sides with respect to
gives
Differentiating with respect to
gives
So we find that
By the fundamental theorem of calculus, we then know the line integral depends only on the values of
at the endpoints of the path. Therefore
The slope of the line connecting two points (<em>a</em>, <em>b</em>) and (<em>c</em>, <em>d</em>) is
(<em>d</em> - <em>b</em>) / (<em>c</em> - <em>a</em>)
i.e. the change in the <em>y</em>-coordinate divided by the change in the <em>x</em>-coordinate. For a function <em>y</em> = <em>f(x)</em>, this slope is the slope of the secant line connecting the two points (<em>a</em>, <em>f(a)</em> ) and (<em>c</em>, <em>f(c)</em> ), and has a value of
(<em>f(c)</em> - <em>f(a)</em> ) / (<em>c</em> - <em>a</em>)
Here, we have
<em>f(x)</em> = <em>x</em> ²
so that
<em>f</em> (1) = 1² = 1
<em>f</em> (1.01) = 1.01² = 1.0201
Then the slope of the secant line is
(1.0201 - 1) / (1.01 - 1) = 0.0201 / 0.01 = 2.01
After Sally had given 1/9 of her stamps to Andy, she had 280 stamps (since they now have equal shares). So 280 was 8/9 of what she started with, making the 1/9 she handed over equal to 280/8, that’s 35. And Andy was “under” by the same amount she was “over” an equal share, that’s 35 under matching her 35 over, which is 70 altogether.
By all means use algebra but you may find you can reason a word problem through in words.
Answer:
1
Step-by-step explanation:
x² + 5x-5
Let x = -6
(-6)^2 + 5(-6) -5
36 -30 -5
6-5
1
