In calculus, we use derivatives to find the instantaneous rate of change at any point on a graph. To find the average rate of change, we just find the slope of the secant line that intercepts two points on the graph.
We find slope with the following equation:

In this case, we are looking for the slope from x = -1 to x = 1. We have both x values, so next we need the y values.
F(-1) = (-1)^2 - (-1) - 1 = 1
F(1) = (1)^2 - (1) - 1 = -1
Now plug in the x and y values to find the slope:
The answer is -1.
I don’t know what the question is, your just saying that
There are 6 letters, each different
Before MOTHER, words from E , H will come
Words from E = 5! (there are 5 letters to arrange)
Words from H = 5!( there are 5 letters to arrange)
Now words starting by M will come.
First ME will have = 4! (as 4 letters will be arranged)
Then MH = 4!
Now words with MO<span>
</span><span>First words starting with MOE... =3!
And words starting with MOH... =3!
the words starting with MOR... =3!
Now, words starting from MOT will come
words starting with MOTE.. = 2!
then after words starting from MOTH will come and first word will MOTHER
so, total no. of words before MOTHER = 5! + 5! + 2* 4! + 3 * 3!
= 120 +120 + 48 + 18
= 306
so, rank of MOTHER = 307</span>
A linear equation will contain a term in x has the highest degree. For example y = 2x - 5 . A non linear will contain terms with exponents 2 or higher
eg x^2 - 2x - 5 is nonlinear.