Since both α and β are in the first quadrant, we know each of cos(α), sin(α), cos(β), and sin(β) are positive. So when we invoke the Pythagorean identity,
sin²(x) + cos²(x) = 1
we always take the positive square root when solving for either sin(x) or cos(x).
Given that cos(α) = √11/7 and sin(β) = √11/4, we find
sin(α) = √(1 - cos²(α)) = √38/7
cos(β) = √(1 - sin²(β)) = √5/4
Now, recall the sum identity for cosine,
cos(x + y) = cos(x) cos(y) - sin(x) sin(y)
It follows that
cos(α + β) = √11/7 × √5/4 - √38/7 × √11/4 = (√55 - √418)/28
Answer:
yes he is correct. he spent 125% more time
Step-by-step explanation:
his original time spent was 20 hours
he spent a new time which is 25 hours
increased time = 25- 20 = 5 hours
% increase = increase/ original ×100%
%increase = 5/ 20 ×100%
= 1/4 ×100%
= 25%
total increment = 100 + 25 =125%
Answer:
pt B: (-1, -8)
Step-by-step explanation:
(x - 7)/2 = -4
x - 7 = -8
x = -1
(y-6)/2 = -7
y - 6 = -14
y = -8
Answer:
Step-by-step explanation:
What the heck do you mean
136 °Fahrenheit
=
57.7778 °Celsius
If you rounded it, it would be 58 °Celsius.