Question

Tìm tập xác định của các hàm số sau:

1) a) y=tanx+3

b) y=3-4cotx

c) y=tan2x+1

d) y=4-5cot3x

e) \(y=tan\left(x+\dfrac{\pi}{3}\right)\)-3

f) \(y=4-2cot\left(x-\dfrac{\pi}{6}\right)\)

2) a) y=3sinx-4cosx+5

b) y=3cos2x-4sin2x+1

c) \(y=\dfrac{3}{1-cosx}+5\)

d) \(\dfrac{1}{1+cosx}+2\)

e) \(y=\dfrac{sinx+2}{cosx+3}\)

f) \(y=1-\dfrac{2}{sinx-1}\)

g) \(y=2x+\dfrac{3}{1+sinx}\)

h) \(y=x^2-x+\dfrac{1}{sin^2x-sinx}\)

j) y=2tanx-3cotx+5

h) \(y=\sqrt{\dfrac{1-sin^2x}{1+cos^2x}}\)

Answer 1

1:

a: ĐKXĐ: \(x< >\dfrac{\Omega}{2}+k\Omega\)

=>TXĐ: \(D=R\backslash\left\{\dfrac{\Omega}{2}+k\Omega\right\}\)

b: ĐKXĐ: \(x< >k\Omega\)

=>TXĐ: \(D=R\backslash\left\{k\Omega\right\}\)

c: ĐKXĐ: \(2x< >\dfrac{\Omega}{2}+k\Omega\)

=>\(x< >\dfrac{\Omega}{4}+\dfrac{k\Omega}{2}\)

TXĐ: \(D=R\backslash\left\{\dfrac{\Omega}{4}+\dfrac{k\Omega}{2}\right\}\)

d: ĐKXĐ: \(3x< >\Omega\cdot k\)

=>\(x< >\dfrac{k\Omega}{3}\)

TXĐ: \(D=R\backslash\left\{\dfrac{k\Omega}{3}\right\}\)

e: ĐKXĐ: \(x+\dfrac{\Omega}{3}< >\dfrac{\Omega}{2}+k\Omega\)

=>\(x< >\dfrac{\Omega}{6}+k\Omega\)

TXĐ: \(D=R\backslash\left\{\dfrac{\Omega}{6}+k\Omega\right\}\)

f: ĐKXĐ: \(x-\dfrac{\Omega}{6}< >\Omega\cdot k\)

=>\(x< >k\Omega+\dfrac{\Omega}{6}\)

TXĐ: \(D=R\backslash\left\{k\Omega+\dfrac{\Omega}{6}\right\}\)