Answer:
see bottom
Step-by-step explanation:
divide through by 4
x2 - 2x - 3 = 0
x2 - 3x + x - 3 = 0
(x2 - 3x) + (x - 3) = 0
x(x - 3) + 1(x - 3) = 0
(x + 1) (x - 3) = 0
x + 1 = 0 and x - 3 = 0
x = -1 and x = 3
A) is 5 months
b) is option 1 difference of 40
Lidal's price is better
Step-by-step explanation:
Lidal
4 for £2.04
1 for £2.04/4= £0.51= 51 p
Oldi
9 for £4.68
1 for £4.68/9= £0.52= 51 p
Lidal offers better price per roll
A ) cos² x · 1 / sin x - 1 / sin x = - sin x
cos² x - 1 / sin x = - sin x
- sin² x / sin x = - sin x
- sin x = - sin x ( correct )
B ) sin x ( cos x / sin x + sin x / cos x ) = 1 / cos x
sin x · ( cos² x + sin²x ) / sin x cos x = 1 / cos x
sin x · 1 / sin x cos x = 1 / cos x
1 / cos x = 1 / cos x ( correct )
C ) cos² x - sin² x = 1 - 2 sin² x
1 - sin² x - sin² x = 1 - 2 sin² x
1 - 2 sin² x = 1 - 2 sin² x ( correct )
D ) 1/sin²x + 1/ cos²x = 1
cos²x + sin² x / sin² x cos² x = 1
1 / cos² x sin² x = 1
cos²x sin² x ≠ 1
Answer: D ) is not an identity.
<span>An independent variable is exactly what it sounds like. It is a variable that stands alone and isn't changed by the other variables you are trying to measure. For example, someone's age might be an independent variable. Other factors (such as what they eat, how much they go to school, how much television they watch) aren't going to change a person's age. In fact, when you are looking for some kind of relationship between variables you are trying to see if the independent variable causes some kind of change in the other variables, or dependent variables.
</span><span>Just like an independent variable, a dependent variable is exactly what it sounds like. It is something that depends on other factors. For example, a test score could be a dependent variable because it could change depending on several factors such as how much you studied, how much sleep you got the night before you took the test, or even how hungry you were when you took it. Usually when you are looking for a relationship between two things you are trying to find out what makes the dependent variable change the way it does.
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*Hope I helped!*
