You don't even need the picture to solve this one.

You said that h = 5 cot(Θ) , and you said that Θ is 30 degrees.
All you need now is to find the cotangent of Θ, plop that into the equation,
and the solution practically jumps off the paper into your lap.

To find the cotangent of 30 degrees, you can use a calculator, look it up
in a book, read it off of a slide rule if you have one, draw a picture of a
30-60-90 right triangle etc. You'll find that the cotangent of 30 degrees
is √3 . That's about 1.732 .

So your equation is h = 5 (1.732) = 8.66 (rounded)

Apparently, somebody gave you the equation, and asked you to find 'h'.
Once you had the equation, you didn't even need to know that 'h' has
anything to do with a triangle.

5 0

3 years ago

Write the following number as ratios of integers

s2008m [1.1K]

Our goal here is to somehow "surgically remove" the repeating part of the number, so let's start by putting the original value in a variable and messing around with it a bit.

We'll let $x=7.\overline{6}$ . We want to cut the $0.\overline{6}$ bit off completely, so let's create the scalpel that'll let us do that. If $x=7.\overline{6}$ , then we can also say that $10x=76.\overline{6}$ . Maybe I was lying a bit: the $x$ is our real scalpel here, and $10x$ is where we'll be making the cut. Mathematically, a "cut" is almost always shorthand for subtraction, so let's see what our operation (cutting $x$ off of $10x$ ) leaves us with:

$10x-x=76.\overline{6}-7.\overline{6}\\9x=69$

The operation was a success! We can now simply divide either side by 9 to find $x = 69/9$ , which, when reduced by dividing the numerator and denominator by 3, gives us $x=23/3$

7 0

3 years ago