Find the value of SiNx | SiNx | + cosx | cosx | Is this to discuss the positive and negative of SiNx and cosx

Find the value of SiNx | SiNx | + cosx | cosx | Is this to discuss the positive and negative of SiNx and cosx

X is the quadrant angle, not on the axis,
Otherwise, the formula is meaningless
(1) X is the first quadrant angle, SiNx > 0, cosx > 0, the value = 2
(2) X is the second quadrant angle, SiNx > 0, cosx

Given TaNx = 2, find the value of cosx + SiNx of cosx SiNx

(cosx+sinx)/(cosx-sinx)=1+2sinx/(cosx-sinx)=1+2/(1/tanx-1)=1+2/（-1/2）=1-4=-3

Find the maximum value of y = SiNx + cosx on (negative half to zero)

y=sinx+cosx=√2sin(x+π/4)
Y '= √ 2cos (x + π / 4) when - π / 2 ≤ x ≤ 0, - π / 4 ≤ x + π / 4 ≤ π / 4, then: y' > 0, so the function is an increasing function
So: Min {y} = √ 2Sin (- π / 4) = - 1, Max {y} = √ 2Sin (π / 4) = 1

Solve the equation (1 + SiNx) / (1 + cosx) = 2

(1 + SiNx) / (1 + cosx) = 21 + SiNx = 2 (1 + cosx) SiNx = 1 + 2cosx because (SiNx) ^ 2 + (cosx) ^ 2 = 1, so (1 + 2cosx) ^ 2 + (cosx) ^ 2 = 1, that is, 1 + 4cosx + 4 (cosx) ^ 2 + (cosx) ^ 2 = 1, so cosx (5cosx + 4) = 0, so when cosx = 0 or cosx = - 4 / 5 (I) cosx = - 4 / 5, SiNx = 1 + 2cosx = - 3 / 5, then x

Solving equation 2 (1-sinx) = 1-cosx

2-2sinx=1-cosx
So cosx = 2sinx-1
Because (SiNx) ^ 2 + (cosx) ^ 2 = 1
So SiNx ^ 2 + (2sinx-1) ^ 2 = 1
sinx^2+4sinx^2+1-4sinx=1
5sinx^2-4sinx=0
The formula solution is sinx1 = 0, satisfying, sinx2 = 4 / 5, satisfying, SiNx ∈ [- 1,1],

39-1,38+2,37-3,36+1,35-2,34+3…… （）
A 1-1 B -1-1
C 0-1 D 0+1
The correct answer is d

D 0+1
39-1 33-1 ...3-1 2+2 1-3 0+1

17.35 + 6.93-17.35 + 6.93 calculated by simple method

17.35-17.35+6.93×2=13.86
Kindergarten?

17 / 42 x 29 + 29 / 42 x 25 are calculated by simple method

(17/42)x29+(29/42)x25
=(29/42)x17+(29/42)x25
=(29/42)x(17+25)
=(29/42)x42
=29

A simple method of 0.9 - (0.15 + 0.35 △ 5 / 7)

0.9-(0.15+0.35÷5/7)
=0.9-0.15-0.49
=0.9-0.64
=0.26
If you don't understand this question, you can ask,

How to do 112 * 13-13 * 12 in a simple way

112*13-13*12=（112-12）*13=100*13=1300
The law of multiplicative Association of merging congeners