For this questions you need to memorize formula of triangle area. for question 5, just substitute the value into the formula. for Q6 you need to use pythagorean theorem formula to find the lenght of each triangle that i already seperated
Kara runs two laps around a track. It takes her 51.495 seconds to complete her first lap and between 53 and 54 seconds to comple
2 answers:
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Answer:
1. leave the radical symbol and don't try to convert it to a decimal form
2. The approximated value differs from the exact solution and doesn't give a true equation.
3. Depending on the case, if she needs a mathematical answer, the exact value should be used, but for more practical applications, the rounded decimal form would be more usable.
Step-by-step explanation:
The step by step solution to the equation:
1.- Exact solution means that if in the final step when solving for x the value of is not a perfect cube, one needs to leave it indicated as a radical expression (with the radical symbol).
in our case, the cubic root of 189 is not a perfect cube. The factor form of 189 is: , so there is a perfect cube factor (
), but the other factor (7) is a prime number. Therefore 3 can get out of the root, while 7 stays inside.
2.- The equation was solved above, in exact form. Now to solve it giving a decimal approximation, we use a calculator to find the cubic root of 7, which is an irrational number with infinite number of decimals, the first of which we type here:
Therefore, the decimal approximation to the solving for x would be:
Where we rounded to two decimals as requested.
When we replace the exact answer in the original expression, we get a perfect equality:
While if we use the approximate answer, we get:
which is NOT a true equality.
3.- I would stick with the idea of showing the exact answer as answer to the mathematical equation. but for a practical case (for example she needs to by some material as a result of her equation solving, it would be more practical to take the numerical approximation to the store, instead of a cubic root of a number.