How to input 3^2x . Sqrt(9) =729 the answer is 3

3^2x . Sqrt(9) = 729

[Torsten]

So

3^6 * sqrt(9) = 3^7 = 729 

?

Or how should I interprete

3^2x . Sqrt(9) 

?

[Muhammad syafikh Mohd umar]

I mean 3 power of 2x multiply square root 9 equal to 729 find x

[Muhammad syafikh Mohd umar]

And the answer is 3.how to put the input

[Torsten]

The answer is not 3, but 2.5.

f = @(x) 3.^(2*x) * sqrt(9) - 729;
x = fzero(f,1) 

[Muhammad syafikh Mohd umar]

Yes youre right thankyou very much

[Torsten]

And does

f = @(x) 3.^(2*x) * sqrt(9) - 729;
x = fzero(f,1) 

answer your question on how to get x ?

[Muhammad syafikh Mohd umar]

Answer 1

[Sam Chak]

Hi @Muhammad syafikh Mohd umar

Unsure of what the 'x' mean in the line. If x means multiplication, then enter this:

(3^2)*sqrt(9)

ans = 27

In Math:

Edit:

Since you have clarified that,

fun = @(x) (3^(2 + x))*sqrt(9) - 729; % function
x0 = 2; % initial point
x = fzero(fun, x0)

x = 3

This assumption satisfies the equation.

[Muhammad syafikh Mohd umar]

X is algebra

[Muhammad syafikh Mohd umar]

The question is 3 power of 2x multiply by square root 9 equal 729. Find x.the answer is 3

[Sam Chak]

I have edited the answer. Please check if the equation looks like this:

[Torsten]

@Sam Chak

Why 3^(2+x) ? It's 3^(2*x) ...

[Sam Chak]

Hi @Torsten

I just made an educated guess only , and that maybe @Muhammad syafikh Mohd umar copied/pasted the equation wrongly. Or, perhaps your answer x = 2.5 is the correct one, but there is a typo in his answer sheet: x = 3. Printing errors in exercise books are common. :-)

[Muhammad syafikh Mohd umar]

This is the question

[Muhammad syafikh Mohd umar]

My apologies the answer is 2.5

[Image Analyst]

What is the symbol after the 2 in the exponent?

[Muhammad syafikh Mohd umar]

X

[Sam Chak]

Hi @Muhammad syafikh Mohd umar

Just a bit curious. This problem seems related to Indices and Logarithms in High School Math. Does the teacher require solving it with MATLAB? Or you just want to confirm the answer using any computational software, like MATLAB?

[Muhammad syafikh Mohd umar]

Yes by using modern tool and i dont know how to put input in matlab

[Sam Chak]

@Muhammad syafikh Mohd umar

Thanks for your reply. If a single variable math problem can be transformed into a root-finding problem, , then you can use fzero to find the solution in most cases. For more info, please check out:

https://www.mathworks.com/help/matlab/ref/fzero.html

[Muhammad syafikh Mohd umar]

Thankyou very much for helping me