A historian is exploring the demographic patterns in West Africa's high forest zone. Which historical factor best explains the hig population density in this area? a. Absence of significant slave raids b. Consistent low temperatures c. Frequent and devastating wars d. Lack of fertile soils for agriculture

(ix) The equation \( \frac{1}{r r} \frac{\partial}{r}\left(r \frac{\partial u}{r r}\right)=\frac{1}{c^{2}} \frac{\partial^{2} u}{\partial t^{2}} \) is one dimensional wave equation in: (a) Cylindrical coordinate (b) Polar coordinate (c) Spherical coordinate (d) None of these

Pemilik sebuah restoran perlu membayar cukai perkhidmatan kepada kerajaan kerana nilai perkhidmatan bercukai yang disediakan restorannya melebihi nilai ambang RM1 500000 setahun. Pihak manakah yang bertanggungawab mengutip cukai ini? The owner of a restaurant is required to pay service tar to the government because the value of taxable services provided by his restaurant exceeds the threshold of RM1 500000 per year. Which entity is responsible for collecting sales and service tax? A Majlis Perbandaran B Lemicipal Council B Inland Revenue Board (IRB) C Pejabat Tanah dan Galian D State Land Office Dabatan Kastam Diraja Malaysia (JKDM) Royal Malaysian Customs Department (RMCD)

(b) Show that the relation R on the set \( \mathrm{A}=\{1 \), \( 2,3,4,5\} \) given by \( \mathrm{R}=\{(\mathrm{a}, \mathrm{b}):|\mathrm{a}-\mathrm{b}| \) is even \( \} \) is an equivalence relation.

) Een zwembad bevat 10000 US gallons. Hoeveel \( m^{3} \) is dat

5. A psychologist is interested in exploring the effect of utorial suppot on students' academic performance and assign students into two groups. Students in group one the tutorial support and those in groupltwo do not. In this example, what is the a) Dependent variable b) Independent variable c) Control group d) Experimental group