If cos (π / 4-A) cos (π / 4 + a) = (√ 2) / 6 (0 < a < π / 2), then sin2a =?

RELATED INFORMATIONS

• 1. Given that a and B are acute angles, and sin (a + b) = 4 / 5, cos (a-b) = 3 / 5, is the first sin2a of sin2a and cos2a equal to 24 / 25?
• 2. It is known that cos (a + (1 / 4) PI) = 3 / 5 and PI / 2
• 3. Under the simplified radical [1-cos (a-pi)] 2 -3pi
• 4. Cos (a + b) = 12 / 13, cos (a-b) = - 12 / 13, and A-B belongs to (PI / 2, PI), a + B belongs to (3pi / 2,2pi) find cos2a-cos2b
• 5. First, cos (a + b) = 4 / 5. Cos (a-b) = - 4 / 5. A + B ∈ [7pi / 4,2pi]. A-B ∈ [3pi / 4, PI]. Cos2a =? Second, prove tan（ The second problem proves that Tan (θ + π / 4) = [Tan θ + 1] / [1 - Tan θ]
• 6. cos(a+β)=3/5,cos(a-β)=12/13,0
• 7. How to calculate the binary value of 110.110... With maple 110.110... Is a decimal with infinite cycles
• 8. Maple / Matlab symbolic operation There is a problem for a long time Is there any way to define an n-dimensional vector (or matrix) in MATLAB or maple, but n does not need to be assigned, and then symbolic operation? For example, I need to derive a function: l = 0.5 * w (T) · V · W, Where W is a variable, an n-dimensional vector, w (T) is its transpose vector; V is an n * n coefficient matrix; n > 1 is an integer In the symbolic operation of maple or MATLAB, can l be derived without n assignment? The derivation of L is very simple. It's a general formula. The problem is how to do symbolic operation on a general formula like this in the program?
• 9. Various methods of finding limit and calculus,
• 10. How to use Maple to solve calculus equation
• 11. In △ ABC, cos (PI / 4 + a) = 5 / 13, then sin2a=
• 12. Given sin2a = 24 / 25, a ∈ (0, π / 2), then cos (a + π / 2) =?
• 13. If the eigenvalues of matrix A of order 3 are known to be 1, - 1 and 2, then the eigenvalues of matrix A2 + 2E are
• 14. Who can help calculate the maximum eigenvalue of the following 21 order matrix Each line element is 1=0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 2=1 0 1 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0 0 0 3=1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 4=1 0 0 0 1 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 5=1 0 0 1 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 6=1 0 0 0 1 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 7=1 0 0 1 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 8=1 0 0 0 1 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 9=1 0 0 1 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 10=0 1 0 0 0 0 0 0 0 0 1 0 1 0 1 0 0 0 0 0 0 11=0 1 0 0 0 0 0 0 0 1 0 1 0 1 0 0 0 0 0 0 0 12=0 1 0 0 0 0 0 0 0 0 1 0 1 0 1 0 0 0 0 0 0 13=0 1 0 0 0 0 0 0 0 1 0 1 0 1 0 0 0 0 0 0 0 14=0 1 0 0 0 0 0 0 0 0 1 0 1 0 1 0 0 0 0 0 0 15=0 1 0 0 0 0 0 0 0 1 0 1 0 1 0 0 0 0 0 0 0 16=0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 17=0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 0 18=0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 19=0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 0 20=0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 21=0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 0
• 15. Please use matlab to calculate the maximum eigenvalue of this matrix and the corresponding eigenvector A= 1 2 3 3 2 1/2 1 2 2 2 1/3 1/2 1 1 2 1/3 1/2 1 1 2 1/2 1/2 1/2 1/2 1
• 16. Who can help me use matlab to calculate the maximum eigenvalue of the matrix and the eigenvector corresponding to the maximum eigenvalue, 1 1/7 1/3 7 1 1/5 3 5 1 1 1/3 3 3 1 5 The 1 / 3 1 / 5 1 matrix is like this
• 17. Use matlab to calculate the maximum eigenvalue of this matrix and its corresponding eigenvector? 1 2 1 3 2 1/2 1 1/3 2 1 1 3 1 4 2 1/3 1/2 1/4 1 2 1/2 1 2 1/2 1
• 18. Matlab calculates the maximum eigenvalue of the matrix and the eigenvector corresponding to the maximum eigenvalue 1 1/7 1/3 7 1 1/5 3 5 1
• 19. Help use matlab to calculate all eigenvalues of the matrix and the eigenvector corresponding to the maximum eigenvalue 1 1/2 1/3 1 1 2 2 5 2 1 1/2 2 2 1 1 5 3 2 1 2 5 5 3 7 1 1/2 1/2 1 1 3 2 5 1 1/2 1/5 1 1 3 2 4 1/2 1 1/5 1/3 1/3 1 1 3 1/2 1 1/3 1/2 1/2 1 1 3 1/5 1/5 1/7 1/5 1/4 1/3 1/3 1
• 20. Is the number of eigenvalues equal to the order of the matrix (square matrix)!