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Is the line coplanar
Mark a vector on two lines, such as AB (vector) CD (vector). If AB (vector)=kCD (vector), then the two lines are coplanar. By the way, we give you some extensions. If the two vectors a, b are not collinear, then the necessary and sufficient condition for the vector p to be collinear with the vectors a, b is that there is a real number pair x, y, so that p=xa+yb.
If AB (vector) CD (vector) AB (vector) CD (vector). If AB (vector)=kCD (vector), then the two lines are coplanar. By the way, we give you some extensions. If the two vectors a, b are not collinear, then the necessary and sufficient condition for the vector p to be collinear with the vectors a, b is that there is a real number pair x, y, so that p=xa+yb.
Please tell me if two sentences are right or wrong. If so, please tell me what is wrong. 1. If x+y=5, then x=2 or y=3. 2. The solution set of the root number (2x-1)3y+3|=0 is {x=1/2y=-1}
The set of solutions for a point is denoted by (x, y), i.e.(1/2,-1)
Given sin (30 degrees + x)=3/5,60 degrees
Sin (30+x)= sin30*cosx+cos30*[(3*Root 3)+4]/10=3/5 That's right
Cosx is wrong. The equation is wrong.
Cosx=4(9-4 pcs.3)/11
Senior one in math. If sina+sinb=1/(root number 2) is known, what is the value range of cosa+cosb? Let t/(root 2)= sinacosa + sinacosb + sinbcosa + sinbcosb =0.5 sin (2a)+0.5 sin (2b)+ sin (a+b), then t/(root 2)= sinacosa + sinbcosb =0.5 sin (2a)+0.5 sin (2b)+ sin (a+b).
When your maximum and minimum values, the values of a and b do not meet the condition sina+sinb=1/(root number 2)
You use the product, I use the sum of squares
1/2+T^2=1+1+2sinasinb+2cosacosb=2+2cos (a-b)
So cos (a-b)=1/2*t^2-3/4>=-3/4
When cos (a-b)=1, t can take the maximum and minimum values, which are ± root (7/2)
At maximum, a=b=arcsin (root 2/4)
At minimum, a=b=π-arcsin (root 2/4)
[Senior Mathematics] Judge the circle size and symbol 》》》 Sin1- cos1 Is it greater than 0 or less than 0? Write the whole process of solving, the answer is: Because (π/4)<1<(π/2) From the trigonometric function line, we can get: sin1>(root number 2)/2> cos1, So sin1- cos1>0 How do you get it? How do you know that sin1 is bigger than him and cos is smaller than it? Please do a concise and forceful explanation. Thank you!
Within (0,π/2) interval
X∈(0,π/4) sinx < cosx
X∈(π/4,π/2) sinx > cosx
Because (π/4)<1<(π/2)
So sin1> cos1
So sin1- cos1>0
∈{ What does each of them mean? What is the difference between them? I want a reason, please explain in detail, ∈{,...,}{|} What does it mean and what is the difference between them? I want a reason. Please elaborate.
The first is "belong to ", which means that an" element "belongs to a" set ", which means that this "element" is in the "set ". The second, in general, is a" set ", in curly brackets are all the "elements" in the set, the third,{|} also means the set, but with constraints: the area in front of the vertical line,...
The first is "belong ", which means" belong "to" belong "to a" set ", which means "element" in the "set ". The second, in general, is a" set ", in curly brackets is the "element" in the set, the third,{|} also means the set, but with constraints: the area in front of the vertical line,...
The first is "belong to ", which means that an" element "belongs to a" set ", which means that the "element" is in the "set ". The second, in general, is a" set ", and the brackets are all in the "element" of the set. The third,{|}, also represents the set, but has constraints: the area in front of the vertical line,...
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