2 answers:
Answer:
Step-by-step explanation:
Remember that for two functions to be inverses, the following must be true:
Since we know they <em>are </em>indeed inverses, they are true.
So, whatever input we put in, we'll just get it back out again.
So, for our first problem:
We can rewrite this as:
We can imagine our x being 3 here.
Therefore, using the above identity, we can conclude that:
For our second example, the same thing:
This is the same as saying:
Again, using the above property, we can imagine our x is -4b. So, this will be equivalent to:
And we're done!
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Answer:
Step-by-step explanation:
STEP 1:
The equation at the end of step 1
STEP 2:
The equation at the end of step 2:
STEP 3:
STEP 4: Pulling out like terms
<u>4.1</u> Pull out like factors:
Trying to factor by splitting the middle term
<u>4.2</u> Factoring
The first term is, its coefficient is 1.
The middle term is, its coefficient is -2.
The last term, "the constant", is +1.
Step-1: Multiply the coefficient of the first term by the constant 1 • 1 = 1
Step-2: Find two factors of 1 whose sum equals the coefficient of the middle term, which is -2.
-1 + -1 = -2 That's it
Step-3: Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -1 and -1
x4 - 1x2 - 1x2 - 1
Step-4 : Add up the first 2 terms, pulling out like factors :
x2 • (x2-1)
Add up the last 2 terms, pulling out common factors :
1 • (x2-1)
Step-5 : Add up the four terms of step 4 :
(x2-1) • (x2-1)
Which is the desired factorization
Trying to factor as a Difference of Squares:
4.3 Factoring: x2-1
Theory : A difference of two perfect squares, A2 - B2 can be factored into (A+B) • (A-B)
Proof : (A+B) • (A-B) =
A2 - AB + BA - B2 =
A2 - AB + AB - B2 =
A2 - B2
Note : AB = BA is the commutative property of multiplication.
Note : - AB + AB equals zero and is therefore eliminated from the expression.
Check : 1 is the square of 1
Check : x2 is the square of x1
Factorization is : (x + 1) • (x - 1)
Trying to factor as a Difference of Squares:
4.4 Factoring: x2 - 1
Check : 1 is the square of 1
Check : x2 is the square of x1
Factorization is : (x + 1) • (x - 1)
Multiplying Exponential Expressions:
4.5 Multiply (x + 1) by (x + 1)
The rule says : To multiply exponential expressions which have the same base, add up their exponents.
In our case, the common base is (x+1) and the exponents are :
1 , as (x+1) is the same number as (x+1)1
and 1 , as (x+1) is the same number as (x+1)1
The product is therefore, (x+1)(1+1) = (x+1)2
Multiplying Exponential Expressions:
4.6 Multiply (x-1) by (x-1)
The rule says : To multiply exponential expressions which have the same base, add up their exponents.
In our case, the common base is (x-1) and the exponents are :
1 , as (x-1) is the same number as (x-1)1
and 1 , as (x-1) is the same number as (x-1)1
The product is therefore, (x-1)(1+1) = (x-1)2
Final result :
4 • (x + 1)2 • (x - 1)2
Answer:
B = 45°
BC = 14 km
AB = 14√2 km ≈ 19.80 km
Step-by-step explanation:
If one acute angle (A) of a right triangle is 45°, then the other one is also:
... 180° -90° -45° = 45°
The sides opposite these congruent angles are the same length, 14 km in this case, and the hypotenuse is found from the Pythagorean theorem to be √2 times either leg length.
... AB² = AC² +BC²
... AB = √(AC² +BC²) = (14 km)√(1² +1²) = 14√2 km
