write a function called tri_area returns the area of a triangle with base b and height h

hello this is my function code and command window code and there is a message of invalid expression at line 2 and i dont know what is the wrong can anyone help me

function [area] = tri_area([b,h]);
tri_area([b,h])=(0.5)*(b)*(h)
area=tri_area([b,h])
end

%command window
area = tri_area[3,2])

[Tushar Tahelramani]

actually my code wgich is similar almost similar to yours work well for 1st assessment of tri_area[3,2] , but second assessment indicates RANDOM INPUTS for that i don't know what to do

plz help me

[pramod kumar jaipal]

for randam input

[Mujibur Rahman]

function [area, tri_area]= tri_area (b, h)
    
    area=(1/2)*(b)*(h)
    vca = area(:);
    tri_area = sum(vca);
end

[Hrvoje Rogulj]

function [area, tri_area]= tri_area (b, h)

area=(1/2)*(b)*(h)

end

[Abdullah Javed]

Make a little change in your code and it will work.

function [area] = tri_area(b,h)
tri_area(b,h)=(0.5)*(b)*(h)
area=tri_area(b,h)
end

[Walter Roberson]

this will not work for inputs that are not positive integers.

[Naveen Gehlot]

function [area, tri_area]= tri_area (b, h)
    
    area=(1/2)*(b)*(h)
    vca = area(:);
    tri_area = sum(vca);
end

use this function for randow inputs

it will works.

[Nur Ameera Nabila Abdul Rahim]

do you mind explaining to me line 3 & 4

Thanks !

[Walter Roberson]

Assuming that Nur Ameera Nabila Abdul Rahim is addressing Naveen Gehlot then:

area=(1/2)*(b)*(h)

is just the standard formula for the area of a triangle.

    vca = area(:);
    tri_area = sum(vca);

That is one way of calculating the total area, which is something that might potentially be done if the user asked to calculate the area for multiple triangles at the same time. However, if the user did ask to calculate for multiple triangles at the same time, it is fairly likely that area=(1/2)*(b)*(h) would be the wrong formula, and that it should instead be

    area=(1/2)*(b).*(h);

or better

    area = (1/2) .* b(:) .* h(:);

[Christine Mizzi]

What is the purpose for writing two output arguments in the code? i.e. [area, tri_area]

If the user is calling the area of a triangle wouldn't that be only one output argument?

[Noor Fatima]

tri_area(b,h)=(b*h)/2 area=tri_area(b,h) %command window area = tri_area(2,3)

[Noor Fatima]

Can any help in finding error bcz it does not gives answer 3

[Torsten]

tri_area = @(b,h) (b*h)/2;
area = tri_area(2,3)

area = 3

[Noor Fatima]

Here random input means can anyone help me

[Walter Roberson]

tri_area(rand(), rand())

[Noor Fatima]

Thanku Walter roberson

Answer 1

[Torsten]

function area = tri_area(b,h)
    area = 0.5*b*h;
end

From the command window

A = tri_area(3,2)

[Ayush Khandelwal]

Error show

[Walter Roberson]

what error shows up?

[ayya aqdas]

what is the answer for random inputs here?

[Walter Roberson]

>> tri_area(rand,rand)

ans =

          0.19421832587356

>> tri_area(rand,rand)

ans =

        0.0299210820832802

>> tri_area(rand,rand)

ans =

         0.362726197496423

[Aadesh Navade]

how to convert the negative values into positive

[Walter Roberson]

You should consider whether you really should convert negative values into positive: negative area has uses.

https://en.wikipedia.org/wiki/Shoelace_formula

[Ishan Pai]

how should we get the random inputs correct ?

[Walter Roberson]

Is there reason to believe that the code is currently processing them incorrectly? What inputs are being used and what response does your code give and what is the expected result?

[SUMANT KUMAR]

still not working

[Walter Roberson]

What difficulty do you observe with this code? What inputs to it are giving the wrong answer?

[SUMANT KUMAR]

Done it. Nothing wrong with the code. There was a problem in random inputs.

[AKASH Talapatra]

kindly can anyone point out me where I was wrong?

[Alric Duarte]

someone please tell the solution for random inputs. i got the same error as above

[Walter Roberson]

See https://www.mathworks.com/matlabcentral/answers/446968-what-is-wrong-with-my-function#comment_839985 for why AKASH Talapatra's code does not work.

[tahmina zaman mitoshi]

can anyone please tell the random input?

[Walter Roberson]

The random input is 7 and 9.3

[Walter Roberson]

Have you considered adding disp statements so you can see what parameters are being passed for the random input case?

[Eshan Pansare]

How to solve the random inputs part?

[Anees Fatima]

what will be the random input here?

[Muhammad Umer]

why this random input is not working.

[Walter Roberson]

When you use the debugger and format long g then what are some sample inputs, and what is the calculated output, and what does the grading program say that the output should be?

Answer 2

[Imane Tahar]

function area = tri_area(b,h)
area = (b*h)/2
end

Answer 3

[Siya Desai]

function

function [area] = tri_area (b,h)
tri_area = (0.5)*(b)*(h)

code to call your function

tri_area(2,3)         %any random input 

[Walter Roberson]

result = tri_area(2,3)         %any random input 

tri_area = 3

Output argument "area" (and maybe others) not assigned during call to "solution>tri_area".

function [area] = tri_area (b,h)
tri_area = (0.5)*(b)*(h)
end

Answer 4

[Pelden Chodon]

function [area, tri_area] = tri_area(b,h) ;
area = (0.5)*(b)*(h);
v = area(:);
tri_area = sum(v);
end

% Test that your function runs as expected before pressing Submit
[area, tri_area] = tri_area(2,3)

[DGM]

You're declaring a variable with the same name as the function you're calling. This will either throw an error or silently cause other errors, depending on where you put the function.

For scalar inputs, summing area serves no purpose. For nonscalar inputs, the results are either wrong, or will throw an error.

% summing a scalar accomplishes nothing
[allareas totalarea] = tri_area(2,3)

allareas = 3

totalarea = 3

% some nonscalar inputs return the wrong results
[allareas totalarea] = tri_area([2 2; 2 2],[3 3; 3 3])

allareas = 2×2

6 6 6 6

totalarea = 24

% some nonscalar inputs return the wrong number of wrong results
[allareas totalarea] = tri_area([2 2],[3;3])

allareas = 6

totalarea = 6

% some nonscalar inputs fail completely
[allareas totalarea] = tri_area([2 2],[3 3])

Error using *
Incorrect dimensions for matrix multiplication. Check that the number of columns in the first matrix matches the number of rows in the second matrix. To operate on each element of the matrix
individually, use TIMES (.*) for elementwise multiplication.

Error in solution>tri_area (line 10)
allareas = (0.5)*(b)*(h); % these parentheses serve no purpose

function [allareas, totalarea] = tri_area(b,h)
    allareas = (0.5)*(b)*(h); % these parentheses don't do anything
    v = allareas(:);
    totalarea = sum(v);
end

As this is all largely copy-pasted from other bad answers posted above, I should point out that much of these problems were already openly explained before you posted this. See also: function, array vs matrix operations