Solving for variables in matlab

[Dell]

i need to make a code that can sole the following, finding the value of Sz
given the following vectors

S=[ -6, -6, -Sz]
P=[ 0 -6 -3]
Q=[ 5 4 -9]

i need to make a code that can find Sz so that
a)S $$\bot$$P
b)S$$\bot$$Q
c)S$$\bot$$(PxQ)
d)(SxP)$$\bot$$Q

i have managed to make MATLAB give me a condition for $$\bot$$, for example, what i set up is:

>>Sz=sym('Sz');
>>S=[ -6, -6, -Sz];
>>P=[ 0 -6 -3];
>>Q=[ 5 4 -9];
>>answer=S*P'

matlab returns
answer =

36+3*Sz

and i know that answer=0, therefore Sz=-12, but how do i get MATLAB to tell me that Sz=-12??

 

[swraman]

build a string that is

'36+3*Sz = 0'

teh num2sr() command may help if the answer is not 0 all the timethen its just:
>> solve('36+3*Sz = 0')

 

[Mene]

To solve for Sz in MATLAB, you can use the "solve" function. This function allows you to solve for a variable in an equation or a system of equations. In this case, you can use the "solve" function to solve for Sz in the equation "answer = 0".

The syntax for using the "solve" function is as follows:

solve(equation, variable)

So in your case, you can use the following code:

>> Sz = sym('Sz');
>> S = [-6, -6, -Sz];
>> P = [0, -6, -3];
>> Q = [5, 4, -9];
>> answer = S*P';
>> solve(answer == 0, Sz)

This will return the solution for Sz, which in this case is -12.

You can also use the "solve" function to solve for multiple variables at once. For example, if you wanted to solve for both Sz and P in the equation "answer = 0", you can use the following code:

>> solve(answer == 0, [Sz, P])

This will return the values for both Sz and P that satisfy the equation.

Additionally, you can use the "solve" function to solve for a variable in a system of equations. For example, to solve for Sz in the system of equations "S \bot P" and "S \bot Q", you can use the following code:

>> Sz = sym('Sz');
>> S = [-6, -6, -Sz];
>> P = [0, -6, -3];
>> Q = [5, 4, -9];
>> solve(S*P' == 0, S*Q' == 0, Sz)

This will return the value of Sz that satisfies both equations.

In summary, to solve for variables in MATLAB, you can use the "solve" function and provide the equation or system of equations you want to solve, along with the variable you are solving for.