Proving the Pythagorean Identity Practice Test

$$\left(\frac{a}{c}\right)^2 + \left(\frac{c}{b}\right)^2 = 1$$ follows from $$a^2 + b^2 = c^2$$ by cross-multiplying the ratios

$$\left(\frac{a}{c}\right)^2 + \left(\frac{b}{c}\right)^2 = 1$$ follows from $$a^2 + b^2 = c^2$$ by dividing both sides by $$c^2$$

$$\left(\frac{a}{b}\right)^2 + \left(\frac{b}{a}\right)^2 = 1$$ follows from $$a^2 + b^2 = c^2$$ by dividing both sides by $$ab$$

$$\left(\frac{c}{a}\right)^2 + \left(\frac{c}{b}\right)^2 = 1$$ follows from $$a^2 + b^2 = c^2$$ by dividing both sides by $$c^2$$