Bisection Sqrt5
1. **State the problem:** We want to find the square root of 5 using the bisection method with a tolerance of $10^{-2}$. This means we want to find $x$ such that $x^2 = 5$ with an error less than 0.01.
2. **Set up the function:** Define $f(x) = x^2 - 5$. We want to find the root of $f(x)$, i.e., where $f(x) = 0$.
3. **Choose initial interval:** Since $2^2 = 4 < 5$ and $3^2 = 9 > 5$, the root lies in the interval $[2, 3]$.
4. **Bisection method steps:**
- Compute midpoint $m = \frac{a+b}{2}$.
- Evaluate $f(m)$.
- If $|f(m)| < 0.01$, stop; $m$ is the approximate root.
- Else, if $f(a)f(m) < 0$, set $b = m$; else set $a = m$.
- Repeat until tolerance is met.
5. **MATLAB code example:**
```matlab
f = @(x) x.^2 - 5;
a = 2; b = 3;
tol = 1e-2;
while (b - a)/2 > tol
m = (a + b)/2;
if abs(f(m)) < tol
break;
elseif f(a)*f(m) < 0
b = m;
else
a = m;
end
end
root = (a + b)/2;
disp(root)
```
6. **Result:** Running this code will give an approximate square root of 5 with error less than 0.01.
**Final answer:** The approximate square root of 5 is about $2.236$ with tolerance $10^{-2}$.