2.5
I presume that sin-1x is being used to represent the inverse sin function (I prefer arcsin x to avoid possible confusion). Make use of the trignometirc relationships: cos2θ + sin2θ = 1 ⇒ cosθ = √(1 - sin2θ) cotθ = cosθ/sinθ = √(1 - sin2θ)/sinθ sin(arcsin x) = x Then: cot(arcsin(x)) = √(1 - sin2(arcsin(x))/sin(arcsin(x)) = √(1 - x2)/x ⇒ cot(arcsin(2/3)) = √(1 - (2/3)2)/(2/3) = √(9/32 - 4/32) ÷ 2/3 = √(9 - 4) x 1/3 x 3/2 = 1/2 x √5
A*sin(x) + cos(x) = 1B*sin(x) - cos(x) = 1Add the two equations: A*sin(x) + B*sin(x) = 2(A+B)*sin(x) = 2sin(x) = 2/(A+B)x = arcsin{2/(A+B)}That is the main solution. There may be others: depending on the range for x.
There are infintely many posibilities: Any expression that contains (y-4) or a multiple of it in the denominator. Also, the following trigonometric functions: An expression that contains arcsin(x/y) where abs(x) < 4 Similarly arccos Corresponding conditions for arccosec and arcsec.
2 sin(x)2 - sin(x) - 1 = 0 Let Y=sin(x) then the equation is 2*Y2 - Y - 1 =0 Delta = (-1 * -1) - 4 * 2 * -1 = 9 Y = (1 + sqrt(9)) / 4 or Y = (1 - sqrt(9)) / 4 Y = 1 or Y = -1/2 Then x = Arcsin(Y) and (in radians) x = Arcsin(1) = Pi/2 +2*k*Pi or x=Arcsin(-1/2) = -Pi/6 + 2*k*Pi where k is an integer
They're the same. They're the same.
The integral of arcsin(x) dx is x arcsin(x) + (1-x2)1/2 + C.
The inverse sin function I write as arcsin x. Make use of the trignometric relationships: cos2θ + sin2θ = 1 ⇒ cosθ = √(1 - sin2θ) cotθ = cosθ/sinθ = √(1 - (sinθ)2)/sinθ sin(arcsin x) = x Then: cot(arcsin(x)) = √(1 - (sin(arcsin(x))2)/sin(arcsin(x)) = √(1 - x2)/x ⇒ cot(arcsin(4/7)) = √(1 - (4/7)2)/(4/7) = √(49/72 - 16/72) ÷ 4/7 = √(49 - 16) x 1/7 x 7/4 = 1/4 x √33
2.5
I presume that sin-1x is being used to represent the inverse sin function (I prefer arcsin x to avoid possible confusion). Make use of the trignometirc relationships: cos2θ + sin2θ = 1 ⇒ cosθ = √(1 - sin2θ) cotθ = cosθ/sinθ = √(1 - sin2θ)/sinθ sin(arcsin x) = x Then: cot(arcsin(x)) = √(1 - sin2(arcsin(x))/sin(arcsin(x)) = √(1 - x2)/x ⇒ cot(arcsin(2/3)) = √(1 - (2/3)2)/(2/3) = √(9/32 - 4/32) ÷ 2/3 = √(9 - 4) x 1/3 x 3/2 = 1/2 x √5
NO FALSE
If I read that correctly, you have: cot(sin-1(2/3)) which I understand to mean cot(arcsin(2/3)) which has the value 1/2 x √5 sin(arcsin(x)) = x cos2θ + sin2θ = 1 ⇒ cosθ = √(1 - sin2θ) cotθ = cosθ ÷ sinθ ⇒ cot(arcsin(2/3)) = cos(arcsin(2/3)) ÷ sin(arcsin(2/3) = √(1 - sin2(arcsin(2/3))) ÷ sin(arcsin(2/3) = √(1 - (2/3)2) ÷ (2/3) = 1/3 x √(9 - 4) x 3/2 = 1/2 x √5 As the reciprocal trignometric functions have separate names, eg 1/tan x = cot x, the use of the -1 "power" to indicate the inverse function is possible. However, to avoid any possible confusion, I prefer to use the arc- prefix to indicate the inverse function.
A*sin(x) + cos(x) = 1B*sin(x) - cos(x) = 1Add the two equations: A*sin(x) + B*sin(x) = 2(A+B)*sin(x) = 2sin(x) = 2/(A+B)x = arcsin{2/(A+B)}That is the main solution. There may be others: depending on the range for x.
1.5
There are infintely many posibilities: Any expression that contains (y-4) or a multiple of it in the denominator. Also, the following trigonometric functions: An expression that contains arcsin(x/y) where abs(x) < 4 Similarly arccos Corresponding conditions for arccosec and arcsec.
2 sin(x)2 - sin(x) - 1 = 0 Let Y=sin(x) then the equation is 2*Y2 - Y - 1 =0 Delta = (-1 * -1) - 4 * 2 * -1 = 9 Y = (1 + sqrt(9)) / 4 or Y = (1 - sqrt(9)) / 4 Y = 1 or Y = -1/2 Then x = Arcsin(Y) and (in radians) x = Arcsin(1) = Pi/2 +2*k*Pi or x=Arcsin(-1/2) = -Pi/6 + 2*k*Pi where k is an integer
(7sin(x))/(cos2(x)-6cos(x))/(sin2(x))=0(7sin3(x))/(cos2(x)-6cos(x))=07sin3(x)=0sin(x)=0x=arcsin(0)x=(pi)(n)where n is any whole numberWe only set the top part of the function equal to zero because we know that if the bottom function equals zero then the answer is undefined. Therefore the top function is the only one that will produce a value of zero.