Hello from MrBillDoesMath
Answer:
[email protected] = - sqrt(7)/ 4
which is choice B
Discussion:
This problem can be solved by drawing triangles and looking at ratios of sides or by using the trig identity:
([email protected])^2 + (sin2)^2 = 1
If [email protected] = 3/4
, the
([email protected])^2 + (3/4)^2 = 1 => (subtract (3/4)^2 from both sides)
([email protected])^2 = 1 - (3/4)^2 = 1 - 9/16 = 7/16
So...... taking the square root of both sides gives
[email protected] = +\- sqrt(7)/ sqrt(16) = +\- sqrt(7)/4
But is [email protected] positive or negative? We are told that @ is in the second quadrant and cos(@) is negative in this quadrant, so our answer must be negative
[email protected] = - sqrt(7)/ 4
which is choice B
Thank you,
Mr. B
Answer:
4(2x + 3) - x = 7x + 12
Explanation:
That's what T4L/Edge said
Answer:
x = -31/4 or x = 17/4
Step-by-step explanation:
|4x + 7| − 4 = 20
⇔ |4x + 7| − 4 + 4 = 20 + 4
⇔ |4x + 7| = 24
⇔ 4x + 7 = 24 or 4x + 7 = -24
⇔ 4x = 24 - 7 or 4x = -24 - 7
⇔ 4x = 17 or 4x = -31
⇔ x = 17/4 or x = -31/4
1/16 = 10 minutes
10 minutes x 6 = 60 minutes
60 minutes = 1 hour
1/16 x 6 = 6/16
he would walk 6/16 in an hour
Answer:
See proof below
Step-by-step explanation:
One way to solve this problem is to "add a zero" to complete the required squares in the expression of xy.
Let 
and 
with 
. Multiplying the two equations with the distributive law and reordering the result with the commutative law, we get 
Now, note that 
by the commutativity of rational integers. Add this convenient zero the the previous equation to obtain 
, thus xy is the sum of the squares of 
.
