The equation \(\left \lfloor{t}\right \rfloor=2t+3\) can be a tad difficult to parse. Sometimes, it is better to think of an easier problem before attempting one a harder one. Let's think about a basic equation that contains the floor function.
\(\left \lfloor{t}\right \rfloor=5\)
Before we can solve this, though, we have to understand the floor function. The floor function truncates any decimal. The solution set for this simplified equation, represented in a compound inequality, is \(5\leq t<6\). Any value for t that satisfies this restriction is a solution. We can use this logic to generalize the floor function, actually to \(\left \lfloor{x}\right \rfloor=a\rightarrow a\leq x < a+1\) . However, you must have caution when doing this, however. Not every solution is actually a solution. I'll touch on this later. Knowing this will be key to solving this equation. Knowing this, the floor function transforms from \(\left \lfloor{t}\right \rfloor=2t+3\) to \(2t+3\leq t<2t+3+1\). Let's solve this compound inequality. I'll solve each one separately.
\(2t+3\leq t\) | Subtract 2t from both sides. |
\(3\leq-t\) | Divide by -1 on both sides. |
\(-3\geq t\) | Of course, the inequality flips when dividing by a negative number. |
\(t\leq -3\) | |
Now, let's solve for the other inequality \(t<2t+3+1\):
\(t<2t+3+1\) | Subtract 2t from both sides. |
\(-t<4\) | Divide by -1 on both sides. Yet again, remember to flip the inequality sign. |
\(t>-4 \) | |
Of course, all solutions must adhere to both restrictions. Both inequalities show that t must be greater than -4 and less than or equal to -3. -3 is automatically a solution because it is an integer.
We aren't done yet, though. Are there are other solution that adhere to our current restriction that makes \(2t+3\) an integer? We don't even have to worry about the +3 because the sum of any integer and 3 will always yield another integer. Let's set this equal to 0:
\(2t+3=0\) | Subtract 3 on both sides. |
\(2t=-3\) | Divide by 2 on both sides. |
\(t=-\frac{3}{2}\) | |
What I have demonstrate here is that a number divided by 2 will make 2t+3 an integer. The only one that meets our description and our current restriction is -(7/2).
Therefore, there are 2 solutions to this equation
\(t_1=-\frac{7}{2}\)
\(t_2=-3\)
.To solve the equation \(0.00000000013284=13284\times10^{-x}\), we must realize that we are trying to get the same base. First, convert \(0.00000000013284\) into a scientific form.
To do this, move the decimal point of \(0.00000000013284\) such that the decimal point moves in front of the first nonzero digit of the number. The number of times one moves is what the 10 will be raised to. Knowing this, \(0.00000000013284=1.3284\times10^{-10}\). We have now changed the equation to the following:
\(1.3284\times10^{-10}=13284\times10^{-x}\)
Now, let's continue moving that decimal of 1.3284 to the right. We'll move it 4 decimal places. This means that \(1.3284\times10^{-10}=13284\times10^{-14}\). Oh look! we have the same base now. Let's solve for x:
\(13284\times10^{-14}=13284\times10^{-x}\) | Divide by 13284 on both sides. |
\(10^{-14}=10^{-x}\) | Our goal is to make the exponents the same. With this equation, the following is implied. |
\(-14=-x\) | Divide by -1 on both sides. |
\(x=14\) | |
And there you go!
I'm assuming that we are solving for v in the equation \(v^2=\frac{25}{81}\). Let's do that!
\(v^2=\frac{25}{81}\) | Take the square root of both sides to isolate v. Of course, the square root always results in 2 answers: The positive and negative. |
\(v=\pm\sqrt{\frac{25}{81}}\) | "Distribute" the square to both the numerator and denominator. |
\(v=\pm\frac{\sqrt{25}}{\sqrt{81}}\) | Now, simplify both the numerator and denominator. |
\(v=\pm\frac{5}{9}=\pm0.\overline{55}\) | |
I can confirm that this answer is correct here. I'm not used to the coding world, so I just used this click-and-drag environment to aid my illiteracy.
To run the mini-program, click the green flag above the head of the cat. Don't blink because it will run in an instant! I have edited the program such that it is generalized for any multiple (under 10), the number you want to detect (also must be under 10) and how many of that number you want to detect (must be under a million). Have fun!
I will solve it for you! The expression I will evaluate is \(\left(\frac{-2}{3}\right)^2\):
\(\left(\frac{-2}{3}\right)^2\) | When you raise a fraction by an exponent, you distribute that exponent to both the numerator and denominator. |
\(\frac{(-2)^2}{3^2}\) | Simplify both the numerator and denominator. |
\(\frac{4}{9}=0.\overline{44}\) | |
By the way, if you would like to type it into a calculator, do it like this: (-2/3)^2. The calculator will output 0.444...