130 likes | 262 Views
Laws of Exponents. x 2 y 4 (xy 3 ) 2. X 2. X 3. Zero Rule. Any non-zero number raised to the zero power equals one X 0 = 1 Examples: 2 0 =1 99 0 = 1. That seems wrong! Anything to the zero power is equal to 1 !?!?.
E N D
Laws of Exponents x2y4(xy3)2 X2 X3
Zero Rule Any non-zero number raised to the zero power equals one X0 = 1 Examples: 20=1 990= 1 That seems wrong! Anything to the zero power is equal to 1 !?!? …Well click on the information button for an explanation!
Rule of One Any number raised to the power of one equals itself. x1=x Examples: 171 = 17 991 = 99 Well this one is easy!
Product Rule When multiplying two powers with the samebase, keep the base and add the exponents. xa • xb = xa+b Examples : 42 • 43 = 45 95• 98 = 913 Now here’s a harder one! (x2y4)(x5y6) = x7y10
Quotient Rule When dividing two powers with the same base, keep the base and subtract the exponents. xa÷ xb = xa-b Examples : 75 ÷ 73 = 72 28÷ 22 = 26 Remember that division can also be written vertically: Now here’s a harder one!
But what happens if you add or subtract the exponents and you get a negative number ? First of all, there is no crying in math! Second, we have a law for that too! It’s called the Negative Rule! Let me tell you all about it…
Negative Rule Any non-zero number raised to a negative power equals its reciprocal raised to the opposite positive power. WHAT!! Click on this button to read more about it!
…Negative Rule Remember that a reciprocal is the multiplicative inverse. In simple terms, flip the fraction! The reciprocal of is . If we apply the negative rule (Any non-zero number raised to a negative power equals its reciprocal raised to the opposite positive power) then, A non-zero raised to a negative power = The reciprocal raised to the opposite power In this example, the negative in front of the four remains. Only the negative of the exponent is effected.
Power Rule When raising a power to a power, keep the base and multiply the exponents. (xa)b = xa•b Let me jot this down. Oh yes, I got it now! Examples: (24)3 = 212 (x3)5 = x15
Product to a Power Rule A product raised to a power is equal to each base in the product raised to that exponent. (x• y)2 = x2y2 Examples: (7• 3)2 = 72 •32 = 49 • 9 =441 (x3y2)5 = x15y10 (2x2yz-3)-4 = 2-4x-8 y-4 z12 = = Here’s one where the variables have exponents Here’s one where the product is raised to a negative power! Tricky, trickier, trickiest – But I think I got it!
Quotient to a Power Rule A quotient raised to a power is equal to each base in the numerator and denominator raised to that exponent. Examples: …and this is the last law!
Why does anything to the zero power equal 1? Take the product for 25 and divide it by 2. 32 ÷ 2 = 16 and 16 = 24 Now take that answer, 16, which is the standard form of 24, and divide it by 2. 16 ÷ 2 = 8 and 8= 23 Now take that answer, 8, which is the standard form of 23, and divide it by 2. 8 ÷ 2 = 4 and 4= 22 Now take that answer, 4, which is the standard form of 22, and divide it by 2. 4 ÷ 2 = 2 and 2 = 21 Now take that answer, 2, which is the standard form of 21, and divide it by 2. 2 ÷ 2 = 1 AND 1 = 20 Division is a good way of showing how this works: 25 = 2 x 2 x 2 x 2 x 2 = 32 24 = 2 x 2 x 2 x 2 = 16 23 = 2 x 2 x 2 = 8 22 = 2 x 2 = 4 21 = 2 = 2 20 = 1 = Really! THIS WORKS FOR ALL NUMBERS – CLICK HERE TO SEE ONE MORE EXAMPLE!
Take the product for 55 and divide it by 5 3125 ÷ 5 = 625 and 625 = 54 Now take that answer, 625, which is the standard form of 54, and divide it by 5 625 ÷ 5 = 125 and 125 = 53 Now take that answer, 125, which is the standard form of 53, and divide it by 5 125 ÷ 5 = 25 and 25 = 52 Now take that answer, 25, which is the standard form of 52, and divide it by 5 25 ÷ 5 = 5 and 5 = 51 Now take that answer, 5, which is the standard form of 51, and divide it by 2. 5 ÷ 5 = 1 AND THEREFORE 1 =50 55 = 5 X 5 X 5 X 5 X 5 = 3125 54 = 5 X 5 X 5 X 5 = 625 53 = 5 X 5 X 5= 125 52 = 5 X 5= 25 51 = 5 = 5 50 = 1 Click to go back to where I left off