Answer:
there's not options :/ nobody can answer this
Answer:
x = 90°
Step-by-step explanation:
Using the identity
cos²x = 1 - sin²x
Given
cos²x - sin x + 1 = 0
1 - sin²x - sin x + 1 = 0
- sin²x - sin x + 2 = 0 ← quadratic equation in sin x ( multiply through by - 1 )
sin²x + sin x - 2 = 0 ← in standard form
(sinx + 2)(sinx - 1) = 0 ← in factored form
Equate each factor to zero and solve for x
sinx + 2 = 0 ⇒ sinx = - 2 ← has no solution as - 1 ≤ x ≤ 1
sinx - 1 = 0 ⇒ sinx = 1 ⇒ x = 90°
solution is x = 90°
Answer:
-10.4
Step-by-step explanation:
-1.3(8)=-10.4
Answer:
a=3
Step-by-step explanation:
This should be very simple, just substitute xy and y for 5 and 7 respectively, so 5a-2*7=1, or 5a-14=1, or 5a=15, if we divide both sides by 5, we get a=3
15 mins = 900 s
We need to find all common multiples of 18 and 42 less than or equal 900.
We'll find the least common multiple first.
18|2
9|3
3|3
1
42|2
21|3
7|7

Now, we nned to find all multiples of 126 that are less than or equal 900.
Those are 126,252,378,504,630,756,882. There are 7 of those.
Therefore the answer is
7.