How to do math problem 7 Ask for advice orz

sin=x,cos=y, then there is the formula x 2 + y 2 = 1, and then xy = -1 8 is told

x-y)^2=5/4

y-x = answer c or d

Because it is an inner angle of a triangle, it is 0, so choose c.

Choose c because is the angle within the triangle, so <180, and sin cos <0, so is the second quadrant angle, so cos -sin <0

So the original formula 2=(cos -sin ) 2=1-2sin cos =5 4 so cos -sin =c

Question 7: Choose C

1) Because it is an angle within a triangle, 0 <180 is also sin cos 1 8<0, that is, sin and cos are different names.

So for the second quadrant angle, 2) because sin cos 1 8 so 2sin cos 1 4

i.e. 2sin cos 1 4

then sin *sin 2sin cos +cos *cos 1 4+1

Therefore (cos sin )*cos sin ) 5 4 i.e. cos sin 5 2 or cos sin 5 2 due to is the second quadrant angle.

So cos 0, sin 0

Hence cos sin 0

So cos sin 5 2

Question 8: Choose A

1) Function f(x) = cos2x-cosx+3(2cosx*cosx-1)-cosx+32cosx*cosx-cosx+2

2cosx 2 4) * (2cosx 2 4) + 15 82) because on the interval ( x< 2).

The maximum value of cosx is 0 and the minimum value is 1

So the function f(x) = (2cosx 2 4) * (2cosx 2 4) + 15 8 max.

And the function f(x) = (2cosx 2 4) * (2cosx 2 4) + 15 8 minimum.

First of all, determine which angle is obtuse.

I didn't learn math well in my freshman year of high school......

<> has a horizontal asymptote line y=0 and a vertical asymptote line x=1.

x->, y has a limit of 0, so the x-axis is a horizontal asymptote.

1m=100cm, 1cm=10mm, 1m=1000mm, 15mm=, greater than. So the first snail won.

|2mx+(1-m²)y-4m-4=0

Set the center of the circle to be (a,b) and the radius to r

The tangent source states that the distance d from the center of the circle to the straight line is equal to the radius r.

r=d=|2ma+(1-m²)b-4m-4|/√[4m²+(1-m²)²

b*m²-(2a-4)m+4-b|(m +1) The value of this equation is independent of m, then 2a-4=0, b=4-b, a=2, b=2r=d=|2m²+2|/(m²+1)=2

The equation for a fixed circle is: (x-2) +y-2) =4

This is a fill-in-the-blank question, and everyone's approach is a waste of time.

There are 2 ways to solve this problem.

The first type:

Solution: Set the single digit to x

x＋x＋3＝9

2x＋3＝9

x 3 thus gives the number 3 3 6 in the ten place

This number is 63

Ask for adoption! Thank you!

Let n=2, the original formula is equal to 2016a2 square-2a1-2a3=2016a2square-2(a1+a3)=0 and because of the difference.

So a1+a3=2a2. Bring in, 2016a2 square-2a2=0, extract the common factor, a2=0 or a2=1 1008.

In the same way, let n = 3, bring it in. The calculated value satisfies the monotonous increase left behind. Again.

Write whatever you want and see if there's anything wrong with it.

(a10c).(2b-c)

Ten = ten. (2b-a).c

Minimum: 3a,b angle 60 degrees.