Hello,
which principle?
f(x)=-x²+2x
==>f'(x)= -2x+2
You mean maybe this

f(x+h)=-(x+h)²+2(x+h)= -(x²+2hx+h²)+2x+2h
f(x)=-x²+2x
Complete question :
Chuck lives 4/5 of a mile from the post office. He walked 2/3 of the way from home to the post office. How far did Chuck walk? If possible, write the answer in reduced form
Answer:
8/ 15 miles
Step-by-step explanation:
Given that:
Distance from house to post office = 4/5 miles
Distance walked = 2/3 of the distance
Hence, the distance walked can be obtained thus :
2/3 of (4/5)
2/3 * 4/5
8 / 15
Hence, Chucks walked 8 /15 miles
The picture is cutted off
25% = 0.25
40 / 0.25 = 160
40 is 25% of 160.
There are 160 children in the club.
Sa = 2pi r h + 2pi r²
= 1327.32 units squared