Realize the tangent function has a period of 180°, so when your calculator (or memory) tells you
.. θ = arctan(-1)
.. θ = -45°
you can translate that value into the desired range by adding multiples of 180° to get the two solutions ...
.. θ = 135°
.. θ = 315°
27 I think..... Oh darn I'm replying to my self
Kim's Loan:
Let A = amount borrowed from bank A.
Let B = amount borrowed from bank B.
The total loan is $55,000.
Therefore
A + B = 55000 (1)
Bank A charges 8% interest. The interest after 1 year is 0.08A.
Bank B charges 11% interest. The interest after 1 year is 0.11B.
Total interest after 1 year is $5,000.
Therefore
0.08A + 0.11B = 5000 (2)
From (1), obtain
B = 55000 - A (3)
Substitute (3) into (2).
0.08A + 0.11(55000 - A) = 5000
0.08A + 6050 - 0.11A = 5000
-0.03A = -1050
A = -1050/-0.03 = 35000
Answer: Kim borrowed $35,000 from bank A.
Jack's Loan.
A = loan from bank A.
B = loan from bank B.
The total loan is $10,000.
Therefore
A + B = 10000 (4)
Bank A charges 5% interest and bank B charges 6% interest.
Total interest after 1 year is $530, therefore
0.05A + 0.06B = 530 (5)
From (4), obtain
B = 10000 - A (6)
Substitute (6) into (5).
0.05A + 0.06(10000 - A) = 530
0.05A + 600 - 0.06A = 530
-0.01A = -70
A = -70/-0.01 = 7000
Answer: Jack borrowed $7,000 from bank A.
3/9<3/8<3/7.
When we have fractions with same numerator, and and different denominators, the fraction that have the lowest denomiator will be the greatest while the one with the highest denomiator will be the smallest.