Let f (Sina + COSA) = Sina * cosa, then the value of F (sin30 degree) is obtained Please write a little more specific, a little afraid Friends who meet at 30 degrees can use six PI

Let f (Sina + COSA) = Sina * cosa, then the value of F (sin30 degree) is obtained Please write a little more specific, a little afraid Friends who meet at 30 degrees can use six PI

Let t = Sina + cosa
Then: sinacosa = [(Sina + COSA) ^ 2-1] / 2 = (T ^ 2-1) / 2
therefore
f(t)=(t^2-1)/2
f(sin30)=f(1/2)
=(1/4-1)/2
=-3/8

-sin30°*-cos60°

-sin30°×(-cos60°)
=-sin30°×（-sin30°）
=（sin30°）^2
=(1/2)^2
=1/4

This equation with trigonometric functions, [(1+sin2x)/(1-sin2x)]+[2(1+tanx)/(1-tanx)]-3=0 How to solve the above equation? X = 2K π or x = 2K π + π or x = k π + arctan2 How is this calculated?

[(1+sin2x)/(1-sin2x)]+[2(1+tanx)/(1-tanx)]-3=(sin²x+cos²x+2sinxcos)/(sin²x+cos²x-2sinxcos)+2(1+sinx/cosx)/(1-sinx/cox)-3=(sinx+cosx)²/(sinx-cosx)²-2(sinx+cosx)/(sinx-cosx...

Matlab inverse trigonometric function >> dot(ta,tb)/(norm(ta)*norm(tb)) ans = -1.000000000000000 >> acos(dot(ta,tb)/(norm(ta)*norm(tb))) ans = 3.141592653589793 - 0.000000021073424i Calculate ACOS (- 1) = Pi separately. Why does the second expression return a complex number instead of Pi?

There will be some errors in numerical calculation
However, since the size of the imaginary part is only 1e-8, it can be ignored
If the subject has any special needs, please indicate

How to use matlab to solve the equations similar to inverse trigonometric function: x + y = 5; arctan (Y / x) + 7 = 5x;

>> syms x y
>> [x,y]=solve('x+y=5','atan(y/x)+7=5*x')
X =
1.6244535398379722718155227031674
Y =
3.3755464601620277281844772968326

Solving an equation with MATLAB Cosh {((x-1) / (x + 1)) * (LN2 / y)} = 0.5 * exp (LN2 / y) when the value of X is known, how to use matlab to calculate the value of Y?

subs(cosh{((x-1)/(x+1))*(ln2/y)}-0.5*exp(ln2/y),{x},{2})

How to use matlab to solve the following equation? The equation is eign-v * eign / Tan (V * eign) + log (V) - log (sin (V * eign)) - 1931 * (1-0.996) = 0; eigen is an independent variable, n eigenvalues of a matrix, and V is a dependent variable. How to solve this equation with MATLAB and draw a two-dimensional graph of dependent variable and independent variable?

syms eign v
eq=eign-v*eign/tan(v*eign)+log(v)-log(sin(v*eign))-1931*(1-0.996);
%If we don't know the value of eign V, we can show the value of eign
ezplot(eq)

Inverse trigonometric function and simplest trigonometric equation In the right triangle ABC, angle c = 90 degrees, angle A

a^2+b^2=c^2
ac=b^2
So a / b = sqrt ((sqrt (3) - 1) / 2)
So a = arctan (A / b) = 31.173952746

Trigonometric function equation problem Solve the following equation for 0°≤x≤360°.(Give the answers correct to 1 decimal place if necessary.) -2 tan ( 3x + 6° ) = 1

-2tan(3x+6°)=1
tan(3x+6°)=-1/2
0°≤x≤360°
0°≤3x≤1080°
6°≤3x+6°≤1086°
The reference angle is 3x+6°=arctan(-1/2)≈-26.5651°
∵tan(3x+6°)<0
∴3x+6° lies in quadrant II or IV.
3x+6°=
180°-26.5651°=153.4°
360-26.5651°=333.4°
540-26.5651°=513.4°
720-26.5651°=693.4°
900-26.5651°=873.4°
1080-26.5651°=1053.4°
∴x=
49.1°
109.1°
169.1°
229.1°
289.1°
349.1°

Equation problems of trigonometric functions sin30/sin54=siny/sinx x+y=48 Find x, y It's best to use junior high school knowledge. I didn't formally learn trigonometric function. Don't underestimate my IQ. I just want to ask whether sin can be arranged

Sin is irreducible! Just like "×" in (20 × 3) / (15 × 2), it can not be reduced
Because x + y = 84, x = 54, y = 30