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Substitute arbitrary values of a and b into the radical equation and see if it is true.
Sometimes
We are asked to analyze the given radical equation.
sqrt(a)+sqrt(b)=sqrt(a+b)
| Sum of Square Roots | Square Root of the Sum | Are the Values the Same? |
|---|---|---|
| sqrt(2)+sqrt(2)≈ 2.83 | sqrt(2+2)= 2 | No |
| sqrt(4)+sqrt(25)= 7 | sqrt(4+25)≈ 5.38 | No |
| sqrt(5)+sqrt(11)≈ 5.55 | sqrt(5+11)= 4 | No |
| sqrt(7)+sqrt(13)≈ 6.25 | sqrt(7+13)≈ 4.47 | No |
As we can see, in each of these examples, we obtained different values for each side of our equation. Therefore, we can disregard the possibility of the answer being always. Now, let's think about whether this equation can be true for some specific values. What if a= 0 and b= 0? sqrt(0)+sqrt(0)&=sqrt(0+ 0) &⇓ 0&=0 ✓ When both a and b equal 0, the equation is true. However, if we try any other values, it will be false. This allows us to conclude that the given equation is sometimes true.