Okay, so in this video we're gonna derive the formula or t is equal to or 1 plus or 2, which is the total resistance of a circuit is equal to the resistance of the 2 or more resistors as long as they are in series. So we're gonna start off by using ohms law and say V1 is equal to i times or 1. So that's for resistor 1 we have ohms law and for resistor 2 we have V2 is equal to i times or 2 for resistor 2. So that's ohms law We know that the total voltage or potential difference is equal to V total is equal to V1 plus V2. I can then replace V1 which I or 1 and V2 with I or 2. So Vt is equal to I or 1 plus I or 2. I can now divide across both sides by I to get Vt over I is equal to or 1 plus or 2 and I know using ohms law again that V over I is equal to or so Vt over I is equal to or t the total resistance or t is equal to or 1 plus or 2