Basically, the question is: how many seconds is h greater than 21? (This tennis ball is being thrown on a planet other than Earth, by the way. I challenge anyone to throw a tennis ball that stays in the air anywhere near as long as this one does.) To figure it out, solve for the (more…)
Think of a 5-12-13 triangle (that’s one of the Pythagorean triples you should know). Say angle A measures x°, which would make angle C measure (90 – x)°. (I’m choosing those based on the fact that I already know that the sine of angle C will be 12/13.) Now that we’ve got it set up, all we (more…)
A function will only have that property if it’s a line that passes through the origin. For example, f(x) = 5x has that property: You can try the same with other linear functions to see why they won’t work. For example, if f(x) = 5x + 2: Nonlinear functions also won’t work. For example, if f(x) (more…)
First, a circle inscribed in a square looks like this: If that square has an area of 2, that means each of its sides has a length of √2. And THAT means that the radius of the circle is √2/2. The area of a circle is πr^2. Plug √2/2 in for r and you’ve got your (more…)
If the actual width is W, then the actual length must be 2W. We know this because in the scale drawing, the length is twice as many inches as the width. The area of the living room floor, therefore will be length times width: from Tumblr https://ift.tt/2mHw9y7
If you remember that the square of i is –1, you can reduce these to purely real numbers before you even FOIL. In a + bi form, 5 is just 5 + 0i, so a + b will be 5 + 0 = 5. from Tumblr https://ift.tt/2A7wbcj
None. The square root of something will never be negative, so if k < 0, it can’t be all alone on the right side of that equation. from Tumblr https://ift.tt/2Aah6qp
Note that f(x) is a line in slope-intercept form, where a is the slope and b is the intercept. Once you recognize that, you just need to know that, notationally, the –2 in front of f(x) means you multiply the whole thing by –2. So: That’s still a line, but now the slope is –2a. from Tumblr (more…)
Note that f(x) is a line in slope-intercept form, where a is the slope and b is the intercept. Once you recognize that, you just need to know that, notationally, the –2 in front of f(x) means you multiply the whole thing by –2. So: That’s still a line, but now the slope is –2a. from Tumblr (more…)
None. The square root of something will never be negative, so if k < 0, it can’t be all alone on the right side of that equation. from Tumblr https://ift.tt/2Oaom8A
If the actual width is W, then the actual length must be 2W. We know this because in the scale drawing, the length is twice as many inches as the width. The area of the living room floor, therefore will be length times width: from Tumblr https://ift.tt/2NEsjBw
Best way to go if you’re not sure is to solve for n. Now all you need to do is find 5/7 of 98. Another way to go is to recognize that if the denominator of 7 is common to both fractions, all you really need to do is divide by 3 and multiply by (more…)
In this question, a boy can either be a junior or a senior. To figure out the minimum number of senior boys, maximize the number of junior boys! Say all 30 juniors are boys. If that’s true, then of the 40 boys in the class, 30 are juniors and the other 10 are seniors. (In (more…)
A question like this on the SAT will always have answer choices, and in this case would be easy to backsolve. Don’t rob yourself of easy points—remember that answer choices are often a helpful tool! Use them to your advantage. In this case, you’d simply need to plug (2x – 1) in for x in each answer choice (more…)
Say x is the number of weeks from this Monday. That means that at the start of the 18th week, they’ll still be OK, but by the end of the 18th week they should have less than 15 bundles. They will order new paper on the Monday of the 19th week. from Tumblr https://ift.tt/2ulT5qd