How many significant figures are there in 1.3070 g?
First, lets review the rules about significant figures. 1. Numbers that aren't 0 are always significant 2. 0s between significant digits are significant 3. leading 0s aren't significant From this information we can conclude that there are 5 significant digits. The first two numbers (1 and 3) aren't 0s so those are significant, making a count of 2. Then according to rule 2, the 0 between 3 and 7 is significant, making the count three. The 7 is also significant according to rule 1, making the count 4 and then the trailing 0 is also significant since it isn't leading (rule 3), making the total count 5.
If f(x) = 3x^2+4x -2. Then what does f(1) equal?
For this problem all you have to do is plug in 1 for all of the x's. Therefore, it would look like this: 3(1)^2+4(1)-2. Now we have to simply this equation. Lets start with the first part - 3(1)^2. 1^2 is still 1. Then we have to times it by 3, equaling 3. Now our equation looks like this: 3+4(1)-2. Now lets work on the second part. 4 * 1 = ? Right, the answer is 4. Now the equation is: 3+4-2. Now lets just simplify this equation. The correct answer would be 5.
Factor this equation: x^2+2x-8
This first step in solving this problem would be to find two numbers that multiply to -8. Those options could be -4 and 2, -2 and 4, 1 and -8, and -1 and 8. Now we have to determine which of these two would add to +2. That answer is -2 and 4. So your equation would be: (x+4)(x-2). To check this answer we would use the FOIL method (first, outside, inside and last). So we would times the first two components of each part, so x * x = x^2. Then we would times the two outsides, so x*-2= -2x. Then the insides, +4*x= 4x. The the lasts, +4 * -2 = -8. Now put all the parts together. x^2 -2x +4x -8 and then simplify this to: x^2+2x-8. This shows that we have the correct factors