# If I have a equation, suppose x.^2+y.^3-10 ; if I put the values of x and y randomly, Can I find the zeroes of this equation at certain values of x and y ? for example x=3 and y=1, there is zero.

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Mahak SINGH CHAUHAN on 11 Mar 2014
Edited: Mahak SINGH CHAUHAN on 27 Sep 2019
If I have a equation, suppose x.^2+y.^3-10 ; if I put the values of x and y randomly, Can I find the zeroes of this equation at certain values of x and y ? for example x=3 and y=1, there is zero. Please help me..

Doug Hull on 11 Mar 2014
ezplot('x^2 + y^3 - 10')

#### 1 Comment

Mahak SINGH CHAUHAN on 11 Mar 2014
Dear Matt J; Thanks for this answer. Could I ask one more thing. If I have have more than two variables like x.^2+y.^2-z.^3 ? Is there any way to find ? I know its complicated and may be, I asked a stupid question

Matt J on 11 Mar 2014
Edited: Matt J on 11 Mar 2014
Given a fixed value of x, you can find one corresponding y at which the expression is zero as follows
x=3;
f=@(y) x.^2+y.^3-10;
y_zero = fzero(f, y_guess);
Although, when f() is a polynomial, as in your example, it would be more efficient to use ROOTS instead of FZERO. Also, ROOTS will find you all solutions y for that x, instead of just one.
Similarly for given y, you can find one associated x as follows
y=1;
f=@(x) x.^2+y.^3-10;
x_zero = fzero(f, x_guess);

#### 1 Comment

Mahak SINGH CHAUHAN on 11 Mar 2014
Thank You very much dear Matt J. Its really helpful.

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