Is the volume of an exemplary cone equal to 4/3(pi)?

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In summary, the conversation discusses an arithmetic error in the equation (4/27)*(3)^3 = 4 and explores the correct way to evaluate it. The participants also discuss the order of operations and the importance of considering floating-point calculations when dealing with integers. The conclusion is that the equation is not equal to 4 and the correct answer is 4/27.
  • #1
5P@N
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How is (4/27)*(3)^3 = 4?

When I evaluate it as a first step, I reduce the (3)^3 into 9, thus generating:

(4/27) * 9.

With a little basic multiplication, I have:
36/27, or 4/3.
Which is obviously not equal to 4!

Am I right or wrong? Where did I make an error?

Take a look if you please at the answer the author of this article has given as regards the volume of an exemplary cone at the beginning of his page. Did he, or did he not make an error in his final calculation? Or am I wrong? My conclusion is that the volume is 4/3(pi).
 
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  • #2
3^3 is not equal to 9 (are you thinking of 3*3 ?)
 
  • #3
Oh. Oops. my bad.
 
  • #4
A small glitch: 3^3 = 27 not 9. Then answer is indeed 4
 
  • #5
5P@N said:
How is (4/27)*(3)^3 = 4?

When I evaluate it as a first step, I reduce the (3)^3 into 9, thus generating:

(4/27) * 9.
Apart from the arithmetic error: This will be wrong if you enter the formula in a C program (or any programming language that handles integers separate from floating point numbers). Assuming 4 and 27 to be integers, 4/27 is 0 (it has to be a non-negative integer less than 1). And even if you do 3^3 as a floating-point calculation, you still have the 0 from the first division...

Thus: when dealing with integers, (4/27)⋅3^3 ≠ (4⋅3^3)/27!
 
  • #6
5P@N said:
How is (4/27)*(3)^3 = 4?
5P@N , the multiply and divide operation are an equal priority operation with left associativity. The power is right associative operation and it's priority is higher than multiply and divide operations. Thus the expression can be written as:
4/27*3^3
and it is really equals 4
 
Last edited by a moderator:
  • #7
##3^3## is not equal to ##9##

##3^3=3×3×3=27##

##\dfrac{4}{27}×27\;\;\implies\dfrac{4}{\not27}×\not{27}=4##

I hope it' ll help.
 

1. How do you solve the equation (4/27)*(3)^3 = 4?

The first step in solving this equation is to simplify the expression on the left side by applying the exponent of 3 to 3, which results in 27. Then, multiply 4 by 27 to get 108. Therefore, the equation becomes 108/27 = 4. Finally, divide 108 by 27 to get the solution of 4.

2. Why does multiplying (4/27) by (3)^3 result in 4?

This is because the exponent of 3 on 3 results in 27, which cancels out with the denominator of 27 in (4/27). This leaves us with 4 as the only remaining number in the numerator, resulting in a final answer of 4.

3. Can you explain the concept of solving equations involving fractions and exponents?

When solving equations involving fractions and exponents, the key is to simplify the expression by applying the exponent to the base number. This will allow you to cancel out any common factors and make the equation easier to solve. Then, you can use basic arithmetic operations like multiplication and division to solve for the unknown variable.

4. Is there a specific order of operations for solving equations with fractions and exponents?

Yes, the general order of operations for solving equations with fractions and exponents is to first simplify the expression by applying the exponent to the base number. Then, multiply or divide any remaining numbers, and finally, add or subtract to solve for the unknown variable.

5. Are there any other ways to solve the equation (4/27)*(3)^3 = 4?

Yes, there are other ways to solve this equation, such as converting all numbers to decimals and using a calculator to solve, or by using the concept of reciprocals (where you flip the fraction and multiply it by the numerator). However, the method explained in the first question is the most commonly used and efficient way to solve this type of equation.

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