CPhill

"Infinity" doesn't behave llike "normal" math operations because it is not a "quantity"....it's a "concept"

Thus

infinity  x infinity = infinity

infinity - infinity = infinity

infinity + infinity = infinity

So....

ininity  = infinity -1

{We also have "orders" of infinity to contend with........}

x = 677/ 45^3  = 0.0074293552812071

The surface area of the cylinder is just  (assuming that pi = 3)

(area of top and bottom) + (area of the side)

(2 x pi x r^2)   + ( 2 x pi x r x h) =

(2 x 3 x 25) + (2 x 3 x 5 x 9) = 420 cm^3

Now...I assume you want to find the edge of a cube that would give you the same surface area....

So we have......

S_a = 6s^2       where s is a side (edge) length of the cube

420 = 6s^2

s^2 = √(420/6)= √70  = about 8.37 cm.

Matt spends 30 x 42 = 1260 p

Bob buys 50 x 22  =    1100 p

You should be able to do it from here....

Just take the square root of 24 = √24 = √(4 * 6) = √4 x √6 = 2√6

Just divide 2000 by 5

x + 9 = 3/2     multiply everything by 2 to clear the fraction

2x + 18  = 3   subtract 1 from both sides

2x = -15        divide both sides by 2

x = -15/2

Hit the "2nd" button on the calculator......you will see the "atan" function  (the tangent inverse)

The radius is given by

√(2*95/ pi)  = r

We can take as many non-zero derivatives as the highest power of the polynomial dictates.

For example....

y = x^2

y' = 2x

y'' = 2

And the third derivative would be  0.