Equal Roots A5Cf04
1. **State the problem:** We are given the quadratic equation $$kx^2 - 4x + 36k = 0$$ and told it has two equal roots with $$k > 0$$. We need to find the value of $$k$$.
2. **Recall the condition for equal roots:** A quadratic equation $$ax^2 + bx + c = 0$$ has two equal roots if its discriminant $$\Delta = b^2 - 4ac = 0$$.
3. **Identify coefficients:** Here, $$a = k$$, $$b = -4$$, and $$c = 36k$$.
4. **Write the discriminant condition:**
$$\Delta = (-4)^2 - 4 \times k \times 36k = 0$$
5. **Simplify the discriminant:**
$$16 - 144k^2 = 0$$
6. **Solve for $$k$$:**
$$144k^2 = 16$$
$$k^2 = \frac{16}{144} = \frac{1}{9}$$
7. **Take the positive root (since $$k > 0$$):**
$$k = \frac{1}{3}$$
**Final answer:** $$k = \frac{1}{3}$$