<span>Inflection points are where the function changes concavity. Since concave up corresponds to a positive second derivative and concave down corresponds to a negative second derivative, then when the function changes from concave up to concave down (or vise versa) the second derivative must equal zero at that point. So the second derivative must equal zero to be an inflection point. But don't get excited yet. You have to make sure that the concavity actually changes at that point.</span>
Step-by-step explanation:
An example : x² + 1 = 0....
Answer:
8 in
Step-by-step explanation:
RA = 4 in, RB = 2 in
oil height in A = hA = 2 in
Find oil height in B = hB
volume of oil in A = VA = π*RA² * hA
equal amount means volume of oil in B VB = VA
But VB = π*RB² * hB
so π*RA² * hA = π*RB² * hB
then
hB = hA *(RA/RB)² = 2 * (4/2)² = 8 in
Answer:

________

Step-by-step explanation:
Given

Line up the numbers

Multiply the top number by the bottom number one digit at a time starting with the ones digit left(from right to left right)
Multiply the top number by the bolded digit of the bottom number

Multiply the bold numbers: 1×4=4

Multiply the bold numbers: 2×4=8

Multiply the top number by the bolded digit of the bottom number

Multiply the bold numbers: 1×1=1

Multiply the bold numbers: 2×1=2

Add the rows to get the answer. For simplicity, fill in trailing zeros.

adding portion

Add the digits of the right-most column: 4+0=4

Add the digits of the right-most column: 8+1=9

Add the digits of the right-most column: 0+2=2

Therefore,

________

The answer is 1/4 because when you add all the numbers up it equals 12 and B or C gives us 3 which simplifies to 1/4