The product of the roots of the equation $x^{2}-3kx+2e^{4In(k)}$ is 31. Then the sum of the root is:
1). 6
2). 2
3). 5
4). 4
The value of tan θ tan(60°+ θ) tan(60° —θ) is:
1). $\frac{1}{4}sin3\theta$
2). $3tan$\theta$
3). $tan3$\theta$
4). $\frac{1}{4}cos3\theta$
The number of real roots of the equation $(7+4\sqrt{3})^{\mid x\mid-6}+(7-4\sqrt{3})^{\mid x\mid-6}=14$ is :
1). 4
2). 3
3). 2
4). 1
The arithmetic mean of the data $(x,f):(8,5),(10,8,(15,8),(20,4)$ is:
1). 12.5
2). 25
3). 12.4
4). 12.8
If $\left(\frac{1-i}{1+i}\right)^{n}$ = 1, then the smallest positive integer n is:
1). 4
2). 1
3). 2
4). 3